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Home My WebLink About8402 Gilman Way_BLD6173_2025 Prescriptive Residential Wood Deck Construction Guide Based on the 2015 International Residential Code Where applicable, provisions and details contained in this document are based on the International Residential Code (IRC) [bracketed text references applicable sections of the IRC]. Prescriptive construction methods recommended meet or exceed minimum requirements of the IRC. Provisions that are not found in the IRC are recommended as good industry practice. Where differences exist between provisions of this document and the IRC, provisions of the IRC shall apply. This document is not intended to preclude the use of other construction methods or materials. All construction and materials must be approved by the authority having jurisdiction. Every effort has been made to reflect the language and intent of the IRC. However, no assurance can be given that designs and construction made in accordance with this document meet the requirements of any particular jurisdiction. Copyright Â© 2018 American Wood Council 2 PRESCRIPTIVE RESIDENTIAL WOOD DECK CONSTRUCTION GUIDE CONTENTS MINIMUM REQUIREMENTS & LIMITATIONS ........... 2 LEDGER BOARD FASTENERS .................................... 15 DECKING REQUIREMENTS ........................................... 3 NON-LEDGER DECKS - VERTICAL LOADS ............. 17 JOIST SIZE ......................................................................... 3 DECK LATERAL LOADS .............................................. 17 BEAM SIZE & ASSEMBLY REQUIREMENTS ............. 5 GUARD REQUIREMENTS ............................................ 19 DECK FRAMING PLAN ................................................... 8 GUARD POST ATTACHMENTS .................................. 19 JOIST-TO-BEAM CONNECTION .................................... 9 STAIR REQUIREMENTS ............................................... 20 JOIST HANGERS .............................................................. 9 STAIR HANDRAIL REQUIREMENTS ......................... 22 POST REQUIREMENTS ................................................. 10 STAIR FOOTING REQUIREMENTS ............................ 22 RIM JOIST REQUIREMENTS ........................................ 11 STAIR LIGHTING REQUIREMENTS ........................... 22 FOOTINGS ....................................................................... 11 FRAMING AT CHIMNEY OR BAY WINDOW ........... 23 LEDGER ATTACHMENT REQUIREMENTS ............... 13 PROHIBITED LEDGER ATTACHMENTS ................... 15 MINIMUM REQUIREMENTS & LIMITATIONS ï‚§ All screws, bolts, washers, nuts, and nails for use 1. This document applies to single level residential with preservative treated wood shall be hot-dipped wood decks that are attached to the house to resist zinc-coated galvanized steel, stainless steel, silicon lateral forces. [R507.2.4] bronze, or copper. Hot-dipped galvanized fasteners shall meet the requirements of ASTM A 2. Overall deck length shall be equal to or less than 153, Class D for fasteners 3/ overall deck width. See DECK FRAMING PLAN for 8" diameter and smaller or Class C for fasteners with diameters definition of deck length and width. over 3/ 8". Stainless steel driven fasteners shall be 3. Minimum post size is 6x6 nominal and maximum post in accordance with the material requirements of height shall be in accordance with Table 4. ASTM F 1667. 4. All lumber shall be identified by the grade mark of, ï‚§ Fasteners other than nails and timber rivets shall or certificate of inspection issued by, an approved be permitted to be of mechanically deposited zinc- lumber grading or inspection bureau or agency coated steel with coating weights in accordance (www.alsc.org). All lumber and glued laminated with ASTM B 695, Class 55, minimum. timber shall be a naturally durable species (such as ï‚§ All connectors (joist hangers, cast-in-place post Redwood or Western Cedars where 90 percent or anchors, etc.) shall be galvanized or shall be more of the width of each side is heartwood); or be stainless steel. Hardware to be hot-dipped prior to preservatively treated with an approved process in fabrication shall meet ASTM A 653, G-185 accordance with American Wood Protection coating. Hardware to be hot-dipped galvanized Association standards (Table 1) [R317 and R318]. after fabrication shall meet ASTM A 123. All lumber in contact with the ground shall be approved preservative treated wood suitable for ï‚§ Fasteners and connectors exposed to salt water or ground contact. [R317.1.2] All cuts shall be field located within 300 feet of a salt water shoreline treated with an approved preservative (such as shall be stainless steel grade 304 or 316. copper naphthenate) [R402.1.2]. ï‚§ Fasteners and connectors shall be of the same 5. All nails shall meet the requirements of ASTM F corrosion-resistant material. 1667. Threaded nails as stated in this document ï‚§ Other coated or non-ferrous fasteners or hardware include helical (spiral) and annular (ring-shank) shall be approved by the authority having nails. Wood screws shall meet the requirements of jurisdiction. ANSI/ASME B18.6.1. Bolts and lag screws shall meet the requirements of ANSI/ASME B18.2.1. 8. Decks supporting large concentrated loads such as hot tubs are beyond the scope of this document. 6. Throughout this document, Â½" diameter bolts and lag screws are specified for various connections. 9. This document does not apply to decks which will Edge distance and spacing requirements are based experience snow loads, snow drift loads, or sliding on Â½" diameter fasteners. If larger (or smaller) snow loads that exceed 40 psf. fasteners are specified, edge distance and spacing 10. Lateral load resistance is limited to the prescriptive shall be adjusted. provisions of R507.2.4 of the IRC. Alternative loads 7. To resist corrosion, the following is required and detailing shall be approved by the authority [R317.3]: having jurisdiction. American Wood Council PRESCRIPTIVE RESIDENTIAL WOOD DECK CONSTRUCTION GUIDE 3 11. Flashing shall be corrosion-resistant metal [R703.8] 12. Decks shall not be used or occupied until final of minimum nominal 0.019-inch thickness or inspection and approval is obtained. approved non-metallic material. Aluminum should 13. This document is not intended to preclude the use of not be used in direct contact with lumber treated other construction methods or materials not described with preservatives that contain copper such as ACQ, herein. Copper Azole, or ACZA. Table 1. Common Species and Use Categories for Decay Resistance.1 Above Ground Species Ground Contact Southern Pine X X 2 Douglas Fir-Larch X X Hem-Fir X X SPF X Ponderosa Pine X X Red Pine X X Preservative-TreatedRedwood X X Western Cedars X 3 Redwood X Naturally DurableWestern Cedars X 1. Use categories listed in Table 1 are based on the American Wood Protection Association (AWPA) Book of Standards. 2. Above Ground â€“ UC3B; Ground Contact â€“ UC4A. 3. Naturally durable species with 90% heartwood in width on each side need not be treated per minimum requirements. DECKING REQUIREMENTS authority having jurisdiction; however, connections equivalent to those shown for lumber or span rated All decking material shall be composed of dimension decking are assumed. lumber (2" nominal thickness) or span rated decking in accordance with the American Lumber Standard JOIST SIZE Committee Policy for Evaluation of Recommended Spans for Span Rated Decking Products (November 5, The span of a joist, L, is measured from the face of 2004). Attach decking to each joist with 2-8d threaded support at one end of the joist to the face of support at nails or 2-#8 screws. Space decking boards the other end of the joist and does not include the length 1 of the overhangs, L approximately /8" apart. See Figure 11 for decking O. Use Table 2 to determine connection requirements at the rim joist. Decking allowable joist span, LJ, based on lumber size and joist placement may range from an angle perpendicular to the spacing. Joist span, L, must be less than or equal to joists to an angle of 45 degrees to the joists. Each allowable joist span, LJ. Overhang length is the lesser of segment of decking must bear on a minimum of 3 joists allowable overhang, LO, or one fourth the joist span, L/4. (or 3 supports). See Figure 1 and Figure 2 for joist span types. Decking not meeting these requirements may be substituted when the product has been approved by the American Wood Council 4 PRESCRIPTIVE RESIDENTIAL WOOD DECK CONSTRUCTION GUIDE Table 2. Maximum Joist Spans and Overhangs.1 Joist Spacing (o.c.) 12" 16" 24" 12" 16" 24" Species Size Allowable Span2 (L 3 J) Allowable Overhang (LO) 2x66 9' - 11" 9' - 0" 7' - 7" 1' - 0" 1' - 1" 1' - 3" 2x8 13' - 1" 11' - 10" 9' - 8" 1' - 10" 2' - 0" 2' - 4" Southern Pine 2x10 16' - 2" 14' - 0" 11' - 5" 3' - 1" 3' - 5" 2' - 10" 2x12 18' - 0"7 16' - 6" 13' - 6" 4' - 6" 4' - 2" 3' - 4" 2x66 9' - 6" 8' - 4" 6' - 10" 0' - 11" 1' - 0" 1' - 2" Douglas Fir- 2x8 12' - 6" 11' - 1" 9' - 1" 1' - 8" 1' - 10" 2' - 2" Larch, Hem-Fir, 4 2x10 15' - 8" 13' - 7" 11' - 1" 2' - 10" 3' - 2" 2' - 9" Spruce-Pine-Fir 2x12 18' - 0"7 15' - 9" 12' - 10" 4' - 4" 3' - 11" 3' - 3" Redwood, 2x66 8' - 10" 8' - 0" 6' - 10" 0' - 9" 0' - 10" 0' - 11" Western Cedars, 2x8 11' - 8" 10' - 7" 8' - 8" 1' - 5" 1' - 7" 1' - 9" Ponderosa Pine5, 2x10 14' - 11" 13' - 0" 10' - 7" 2' - 5" 2' - 7" 2' - 8" Red Pine5 2x12 17' - 5" 15' - 1" 12' - 4" 3' - 7" 3' - 9" 3' - 1" 1. Assumes 40 psf live load, 10 psf dead load, No. 2 grade, and wet service conditions. 2. Assumes L/360 deflection. 3. Maximum allowable overhang cannot exceed L/4 or Â¼ of actual main span. Assumes cantilever length/180 deflection with 220 lb point load (See Figure 1A and Figure 2). 4. Incising assumed for Douglas Fir-Larch, Hem-Fir, and Spruce-Pine-Fir. 5. Design values based on northern species with no incising assumed. 6. Ledger shall be a minimum of 2x8 nominal. Joists and rim joists to which guard posts are attached shall be a minimum of 2x8 nominal. 7. Joist length prescriptively limited to 18'-0" for footing design. Figure 1A. Joist Span â€“ Joists Attached at House and Bearing Over Beam. American Wood Council PRESCRIPTIVE RESIDENTIAL WOOD DECK CONSTRUCTION GUIDE 5 Figure 1B. Joist Span â€“ Joists Attached at House and to Side of Beam. Figure 2. Joist Span â€“ Non-Ledger Deck. BEAM SIZE & ASSEMBLY REQUIREMENTS Joists shall not frame in from opposite sides of the same beam. See JOIST-TO-BEAM CONNECTION details, Deck beam spans shall be in accordance with Table 3 Figure 6. and can extend past the post face up to LB/4 as shown in Figure 3. Joists may bear on the beam and extend past Where multiple 2x members are used, the deckâ€™s beam is the beam face up to the lesser of LO or L/4 as shown in assembled by attaching the members identified in Table Figures 1A and 2, or the joists may attach to the side of 3A in accordance with Figure 4 [Table R602.3(1)]. the beam with joist hangers as shown in Figure 1B. American Wood Council 6 PRESCRIPTIVE RESIDENTIAL WOOD DECK CONSTRUCTION GUIDE Table 3A. Dimension Lumber Deck Beam Spans (L 1 B) Supporting a Single Span of Joists with or without Overhangs. Joist Spans (L) Less Than or Equal to: Species Size4 6' 8' 10' 12' 14' 16' 18' 2-2x6 6' - 8" 5' - 8" 5' - 1" 4' - 7" 4' - 3" 4' - 0" 3' - 9" 2-2x8 8' - 6" 7' - 4" 6' - 6" 5' - 11" 5' - 6" 5' - 1" 4' - 9" 2-2x10 10' - 1" 8' - 9" 7' - 9" 7' - 1" 6' - 6" 6' - 1" 5' - 9" 2-2x12 11' - 11" 10' - 4" 9' - 2" 8' - 4" 7' - 9" 7' - 3" 6' - 9" Southern Pine 3-2x6 7' - 11" 7' - 2" 6' - 5" 5' - 10" 5' - 5" 5' - 0" 4' - 9" 3-2x8 10' - 7" 9' - 3" 8' - 3" 7' - 6" 6' - 11" 6' - 5" 6' - 1" 3-2x10 12' - 9" 11' - 0" 9' - 9" 8' - 9" 8' - 3" 7' - 8" 7' - 3" 3-2x12 15' - 0" 13' - 0" 11' - 7" 10' - 6" 9' - 9" 9' - 1" 8' - 7" 3x6 or 2-2x6 5' - 2" 4' - 5" 3' - 11" 3' - 7" 3' - 3" 2' - 10" 2' - 6" 3x8 or 2-2x8 6' - 7" 5' - 8" 5' - 1" 4' - 7" 4' - 3" 3' - 10" 3' - 5" Douglas Fir- 3x10 or 2-2x10 8' - 1" 7' - 0" 6' - 3" 5' - 8" 5' - 3" 4' - 10" 4' - 5" Larch2, Hem- 3x12 or 2-2x12 9' - 5" 8' - 2" 7' - 3" 6' - 7" 6' - 1" 5' - 8" 5' - 4" Fir2, Spruce- Pine-Fir2, 4x6 6' - 2" 5' - 3" 4' - 8" 4' - 3" 3' - 11" 3' - 8" 3' - 5" Redwood, 4x8 8' - 2" 7' - 0" 6' - 3" 5' - 8" 5' - 3" 4' - 11" 4' - 7" Western 4x10 9' - 8" 8' - 4" 7' - 5" 6' - 9" 6' - 3" 5' - 10" 5' - 5" Cedars, 4x12 11' - 2" 9' - 8" 8' - 7" 7' - 10" 7' - 3" 6' - 9" 6' - 4" Ponderosa Pine3, Red 3-2x6 7' - 1" 6' - 5" 5' - 9" 5' - 3" 4' - 10" 4' - 6" 4' - 3" Pine3 3-2x8 9' - 5" 8' - 3" 7' - 4" 6' - 8" 6' - 2" 5' - 9" 5' - 5" 3-2x10 11' - 9" 10' - 2" 9' - 1" 8' - 3" 7' - 7" 7' - 1" 6' - 8" 3-2x12 13' - 8" 11' - 10" 10' - 6" 9' - 7" 8' - 10" 8' - 3" 7' - 10" 1. Assumes 40 psf live load, 10 psf dead load, L/360 simple span beam deflection limit, cantilever length/180 deflection limit, No. 2 grade, and wet service conditions. 2. Incising assumed for Douglas Fir-Larch, Hem-Fir, and Spruce-Pine-Fir. 3. Design values based on northern species with no incising assumed. 4. Beam depth must be equal to or greater than joist depth if joist hangers are used (see Figure 6, Option 3). American Wood Council PRESCRIPTIVE RESIDENTIAL WOOD DECK CONSTRUCTION GUIDE 7 Table 3B. Glued Laminated Timber Beam Spans (L 1 B) Supporting a Single Span of Joists with or without Overhangs. Joist Spans (L) Less Than or Equal to: Stress Class2 Width3 Depth4 6' 8' 10' 12' 14' 16' 18' 9-1/2" 12'-2" 10'-6" 9'-4" 8'-6" 7'-10" 7'-4" 6'-11" 3-1/2" 11-7/8" 15'-2" 13'-1" 11'-8" 10'-8" 9'-10" 9'-2" 8'-8" Balanced or Unbalanced 20F-1.5E 14" 17'-10" 15'-5" 13'-9" 12'-7" 11'-7" 10'-10" 10'-2" And Higher Grade 11-7/8" 18'-0"5 16'-8" 14'-10" 13'-7" 12'-6" 11'-8" 11'-0" Cedar 5-1/4" 5 5 14" 18'-0" 18'-0" 17'-6" 15'-11" 14'-9" 13'-9" 13'-0" 16" 18'-0"5 18'-0"5 18'-0"5 18'-0"5 16'-10" 15'-9" 14'-10" 9-1/2" 13'-11" 12'-1" 10'-9" 9'-10" 9'-1" 8'-6" 8'-0" 3-1/2" 11-7/8" 17'-5" 15'-1" 13'-5" 12'-3" 11'-4" 10'-7" 10'-0" Unbalanced 24F-1.8E 5 14" 18'-0" 17'-9" 15'-10" 14'-5" 13'-4" 12'-6" 11'- 9" Douglas Fir-Larch or Southern Pine 11-7/8" 18'-0"5 18'-0"5 17'-1" 15'-7" 14'-5" 13'-6" 12'-8" 5-1/4" 14" 18'-0"5 18'-0"5 18'-0"5 18'-0"5 17'-0" 15'-10" 14'-11" 16" 18'-0"5 18'-0"5 18'-0"5 18'-0"5 18'-0"5 18'-0"5 17'-0" 9-1/2" 13'-11" 12'-7" 11'-8" 11'-0" 10'-5" 9'-11" 9'-7" 3-1/2" 11-7/8" 17'-5" 15'-10" 14'-8" 13'-9" 13'-1" 12'-6" 12'-0" Balanced 24F-1.8E 5 5 14" 18'-0" 18'-0" 17'-4" 16'-3" 15'-5" 14'-9" 14'-2" Douglas Fir-Larch or Southern Pine 11-7/8" 18'-0"5 18'-0"5 17'-4" 16'-3" 15'-5" 14'-9" 14'-2" 5-1/4" 14" 18'-0"5 18'-0"5 18'-0"5 18'-0"5 18'-0"5 17'-6" 16'-9" 16" 18'-0"5 18'-0"5 18'-0"5 18'-0"5 18'-0"5 18'-0"5 18'-0"5 1. Assumes 40 psf live load, 10 psf dead load, L/360 simple span beam deflection limit, cantilever length/180 deflection limit. Glued laminated timber shall be of naturally durable species or treated with an oil-borne or water-borne preservative in accordance with AWPA U1. See MINIMUM REQUIREMENTS & LIMITATIONS. Spans for glued laminated timber beams not treated with oil-borne preservatives shall be multiplied by 0.89. 2. Preservative treated structural composite lumber of equal or greater capacity can be substituted. 3. Beam widths of 3-1/8" or wider can be used for the tabulated 3-1/2" width, and beam widths of 5-1/8" or wider can be used for the tabulated 5-1/4" width. 4. Beam depth must be equal to or greater than joist depth if joist hangers are used (see Figure 6, Option 3). 5. Beam span prescriptively limited to 18'-0" for footing design. Figure 3. Beam Span. American Wood Council 8 PRESCRIPTIVE RESIDENTIAL WOOD DECK CONSTRUCTION GUIDE Figure 4. Beam Assembly Details. DECK FRAMING PLAN The overall deck length shall be equal to or less than the overall deck width. Stairs and stair landings shall not be A framing plan shows the width, length, joist and beam included in determining the overall deck length or width. layout; the location of the ledger board, posts, and See Figure 5 for an example of a typical deck framing footings; and the type, size, and spacing of the ledger plan. board fasteners. Figure 5. Typical Deck Framing Plan. American Wood Council PRESCRIPTIVE RESIDENTIAL WOOD DECK CONSTRUCTION GUIDE 9 JOIST-TO-BEAM CONNECTION must have a minimum capacity of 100 lbs in both uplift and lateral load directions. Joists may also attach to the Each joist shall be attached to the beam as shown in side of the beam with joist hangers per Option 3. Joists Figure 6. Joists may bear on and overhang past the beam shall not frame in from opposite sides of the same beam. face the lesser of LO or L/4 when Option 1 or Option 2 is See JOIST HANGERS for more information. Hangers, used to attach the joist to the beam and blocking is clips, and mechanical fasteners shall be galvanized or provided between joists at beam bearing. Mechanical stainless steel (see MINIMUM REQUIREMENTS). fasteners or hurricane clips used, as shown in Option 2, Figure 6. Joist-to-Beam Detail. JOIST HANGERS Figure 7. Typical Joist Hangers. Joist hangers, as shown in Figure 7, shall have a depth of at least 60% of ledger or beam depth. Each hanger shall have a minimum vertical capacity in accordance with Table 3A. The joist hanger shall be selected from an approved manufacturerâ€™s product data based on the dimensions of the joist or header it is carrying. Joist hangers and fasteners shall be corrosion resistant (see MINIMUM REQUIREMENTS). Use joist hangers with inside flanges when clearances to the edge of the beam or ledger board dictate. Do not use clip angles or brackets to support joists. Table 3A. Joist Hanger Vertical Capacity. Joist Size Minimum Capacity, lbs 2x6 400 2x8 500 2x10 600 2x12 700 American Wood Council 10 PRESCRIPTIVE RESIDENTIAL WOOD DECK CONSTRUCTION GUIDE POST REQUIREMENTS Figure 8B. Alternate Approved Post-to-Beam All deck post sizes shall be 6x6 (nominal) or larger, and Post Cap Attachment. the maximum height shall be in accordance with Table 4 and measured from grade or top of foundation, whichever is highest, to the underside of the beam. Under prescriptive limits of this document, 8x8 nominal posts can be substituted anywhere in Table 4 but are limited to a maximum height of 14'-0". Posts shall be centered on footings. Cut ends and notches of posts shall be field treated with an approved preservative (such as copper naphthenate) [R402.1.2]. The beam shall be attached to the post by notching as shown in Figure 8A or by providing an approved post cap to connect the beam and post as shown in Figure 8B. All 3-ply beams shall be connected to the post by a post cap. All through- bolts shall have washers under the bolt head and nut. Attachment of the beam to the side of the post without notching is prohibited (see Figure 9). Figure 9. Prohibited Post-to-Beam Attachment Condition. Provide diagonal bracing parallel to the beam at each corner post greater than 2'-0" in height as shown in Figure 10. Diagonal bracing is prohibited on center posts. Bracing shall be fastened to the post at one end and the beam at the other with Â½" diameter lag screws. For non-ledger decks, (see Figure 21) diagonal bracing may be omitted at the beam and posts adjacent to the house. Figure 8A. Post-to-Beam Attachment Requirements. Figure 10. Diagonal Bracing. American Wood Council PRESCRIPTIVE RESIDENTIAL WOOD DECK CONSTRUCTION GUIDE 11 RIM JOIST REQUIREMENTS Attach a continuous rim joist to the ends of joists as shown in Figure 11. Attach decking to the rim joist as shown in Figure 11. For more decking attachment requirements, see DECKING REQUIREMENTS. Figure 11. Rim Joist Connection Details. FOOTINGS [R403] capacity shall be determined by a soils investigation. DECK FOOTINGS CLOSER THAN 5'-0" TO AN See Figure 12 and Table 4 for footing size, footing EXTERIOR HOUSE FOUNDATION WALL MUST thickness, and post attachment options and requirements. BEAR AT THE SAME ELEVATION AS THE All footings shall bear on undisturbed soil at least 12 FOOTING OF THE HOUSE FOUNDATION. inches below the undisturbed ground surface or below the frost line, whichever is deeper. Contact the authority Do not construct footings over septic systems or leach having jurisdiction to determine the specified frost line. fields, utility lines, or enclosed meters. Contact local Bearing conditions shall be verified in the field by the utilities (call 811) before digging. building official prior to placement of concrete. Where Pre-manufactured post anchors shall be galvanized or the building official determines that in-place soils with stainless steel. See MINIMUM REQUIREMENTS. an allowable bearing capacity of less than 1,500 psf are likely to be present at the site, the allowable bearing American Wood Council 12 PRESCRIPTIVE RESIDENTIAL WOOD DECK CONSTRUCTION GUIDE Table 4. Post Height for 6x65 and Footing Sizes for all Posts. Post Heights1 Footing Sizes2 4 B 3 J 3 , Western Pine 3 Cedars Joist Span LSouthern Redwood Diameter Beam Span, L Ponderosa Pine, Red Pine, SPFRound Footing Square Footing Douglas Fir-LarchHem-Fir Footing Thickness â‰¤10' 14' 14' 14' 14' 14' 18" 16"x16" 7" 6' â‰¤14' 14' 14' 14' 14' 14' 21" 18"x18" 8" â‰¤18' 14' 14' 12' 14' 11' 24" 21"x21" 10" â‰¤10' 14' 14' 14' 14' 14' 20" 18"x18" 8" 8' â‰¤14' 14' 14' 14' 14' 11' 24" 21"x21" 10" â‰¤18' 14' 13' 11' 12' 8' 27" 24"x24" 11" â‰¤10' 14' 14' 14' 14' 12' 23" 20"x20" 9" 10' â‰¤14' 14' 13' 11' 13' 8' 27" 24"x24" 11" â‰¤18' 12' 11' 8' 11' 2' 31" 27"x27" 13" â‰¤10' 14' 14' 12' 14' 10' 25" 22"x22" 10" 12' â‰¤14' 13' 12' 9' 11' 5' 30" 26"x26" 13" â‰¤18' 11' 9' 6' 9' 2' 34" 30"x30" 15" â‰¤10' 14' 13' 11' 13' 8' 27" 24"x24" 11" 14' â‰¤14' 11' 10' 7' 10' 2' 32" 29"x29" 14" â‰¤18' 9' 8' 2' 8' NP 37" 33"x33" 16" â‰¤10' 13' 12' 10' 12' 6' 29" 26"x26" 12" 16' â‰¤14' 10' 9' 5' 9' 2' 35" 31"x31" 15" â‰¤18' 7' 5' 2' 7' NP 40" 35"x35" 18" â‰¤10' 12' 11' 8' 11' 2' 31" 27"x27" 13" 18' â‰¤14' 9' 8' 2' 8' NP 37" 33"x33" 16" â‰¤18' 5' 2' 2' 6' NP 42" 37"x37" 19" 1. Assumes 40 psf live load, 10 psf dead load, LB/4 and LJ/4 overhangs, No 2. grade and wet service conditions. 2. Assumes 1,500 psf soil bearing capacity and 150 pcf concrete. Value may be multiplied by 0.9 for corner posts. 3. Incising assumed for Douglas Fir-Larch, Hem-Fir, and Spruce-Pine-Fir. 4. Assumes 2,500 psi compressive strength of concrete. Coordinate footing thickness with post base and anchor requirements. 5. 8x8 nominal posts may be substituted anywhere in Table 4 to a maximum height of 14'. American Wood Council PRESCRIPTIVE RESIDENTIAL WOOD DECK CONSTRUCTION GUIDE 13 Figure 12. Typical Footing Options. LEDGER ATTACHMENT REQUIREMENTS 13A). Many new homes constructed with wood I-joists [R507] include 1" or thicker laminated veneer lumber (LVLas band joists (or rim joists) that can support the attachment GENERAL: Attach the ledger board, which shall be of a deck (see Figure 14). However, some older homes equal to or greater than the deck joist depth but less than might be constructed with band boards that are too thin or equal to the house band or rim joist depth, to the (less than 1") to support a deck. In such cases, a non- house in accordance with Figures 14 and 15. The ledger ledger deck or a full plan submission is required. shall be a minimum nominal 2x8. When attachments are made to the house band joist, the band joist shall be MANUFACTURED WOOD TRUSS: A metal plate capable of supporting the new deck. If this cannot be connected wood truss (MPCWT) is an engineered, verified or conditions at the house differ from the details prefabricated structural component designed for each herein, then either a non-ledger deck or full plan specific application. MPCWTâ€™s used in residential floors submission is required. See NON-LEDGER DECKS. are often installed with a 2x4 lumber â€œribbonâ€ at the ends of the trusses (see Figure 13B) to tie the ends of the SIDING AND FLASHING: House siding or the trusses together. The ribbon board, by itself, is not exterior finish system must be removed prior to intended to support the deck ledger and deck. Installing installation of the ledger board. Approved corrosion residential decks when the floor system for the house resistant flashing is required at any ledger board uses MPCWT requires a standard detail provided by the connection to a wall of wood framed construction (see truss designer, a non-ledger deck, or a full plan MINIMUM REQUIREMENTS). See Figure 14 for submission. Refer to the Technical Note â€“ Attachment of continuous flashing with drip edge. The threshold shall Residential Deck Ledger to Metal Plate Connected be carefully flashed and caulked to prevent water Wood Truss Floor System for special blocking details intrusion due to splash from the deck or melting snow and attachment requirements (www.sbcindustry.com). and ice. MANUFACTURED WOOD I-JOIST: The term â€œI- Joistâ€ denotes manufactured wood â€œIâ€ joists (see Figure American Wood Council 14 PRESCRIPTIVE RESIDENTIAL WOOD DECK CONSTRUCTION GUIDE Figure 13A. Wood I-Joist Profile. Figure 13B. Metal Plate Connected (MPC) Wood Floor Trusses with a 2x4 Lumber â€œRibbonâ€ at the Ends of the Trusses. Figure 14. General Attachment of Ledger Board to Band Joist or Rim Joist. Figure 15. Attachment of Ledger Board to Foundation Wall (Concrete or Solid Masonry). American Wood Council PRESCRIPTIVE RESIDENTIAL WOOD DECK CONSTRUCTION GUIDE 15 PROHIBITED LEDGER ATTACHMENTS Figure 18. No Attachment to House Overhang Attachments to exterior veneers (brick, masonry, stone), with Ledger. hollow masonry, and to cantilevered floor overhangs or bay windows are prohibited (see Figures 17 and 18). In such cases, the non-ledger deck is required (See NON- LEDGER DECKS). Figure 17. No Attachment to or Through Exterior Veneers (Brick, Masonry, Stone). LEDGER BOARD FASTENERS lumber band joist (1-Â½" actual) or LVL rim joist bearing on a sill plate or wall plate shall be constructed with Â½" Only those fasteners noted below are permitted. LEAD lag screws or bolts with washers per Table 5 and Figure ANCHORS ARE PROHIBITED. 19 (see MINIMUM REQUIREMENTS). Deck ledger connection to band joist or rim joist. The connection between a deck ledger and a 2-inch nominal Table 5. Fastener Spacing for a Southern Pine, Douglas Fir-Larch, or Hem-Fir Deck Ledger or Band or Rim Joist and a 2-inch Nominal Solid-Sawn Spruce-Pine-Fir Band Joist or LVL Rim Joist.3,4,5,6,8 (Deck Live Load = 40 psf, Deck Dead Load = 10 psf) Joist Span Rim Joist 6'-0" 6'-1" 8'-1" 10'-1" 12'-1" 14'-1" 16'-1" or and to to to to to to Band Joist less 8'-0" 10'-0" 12'-0" 14'-0" 16'-0" 18'-0" Connection Details On-Center Spacing of Fasteners 1 1" LVL 24" 18" 14" 12" 10" 9" 8" Â½" diameter lag screw with 1 15 1- /8" LVL 28" 21" 16" 14" 12" 10" 9" /32" maximum sheathing 1-Â½" Lumber 30" 23" 18" 15" 13" 11" 10" 1" LVL 24" 18" 14" 12" 10" 9" 8" Â½" diameter bolt with 1 15 1- /8" LVL 28" 21" 16" 14" 12" 10" 9" /32" maximum sheathing 1-Â½" Lumber 36" 36" 34" 29" 24" 21" 19" Â½" diameter bolt with 15/ 32" maximum sheathing and 1-Â½" Lumber 36" 36" 29" 24" 21" 18" 16" Â½" stacked washers2,7 1. The tip of the lag screw shall fully extend beyond the inside face of the band or rim joist. 2. The maximum gap between the face of the ledger board and face of the wall sheathing shall be Â½". 3. Ledgers shall be flashed or caulked to prevent water from contacting the house band joist (see Figures 14 and 15). 4. Lag screws and bolts shall be staggered per Figure 19. 5. Deck ledgers shall be minimum 2x8 pressure-preservative-treated No.2 grade lumber, or other approved materials as established by standard engineering practice. 6. When solid-sawn pressure-preservative-treated deck ledgers are attached to engineered wood products (minimum 1" thick wood structural panel band joist or structural composite lumber including laminated veneer lumber), the ledger attachment shall be designed in accordance with accepted engineering practice. Tabulated values based on 300 lbs and 350 lbs for 1" and 1-1/8" LVL rim joist, respectively. 7. Wood structural panel sheathing, gypsum board sheathing, or foam sheathing shall be permitted between the band or rim joist and ledger. Stacked washers are permitted in combination with wood structural panel sheathing, but are not permitted in combination with gypsum board or foam sheathing. The maximum distance between the face of the ledger board and the face of the band joist shall be 1". 8. Fastener spacing also applies to Southern Pine, Douglas Fir-Larch, and Hem-Fir band or rim joists. American Wood Council 16 PRESCRIPTIVE RESIDENTIAL WOOD DECK CONSTRUCTION GUIDE Placement of lag screws or bolts in deck ledgers the deck ledger (see Figure 19). Proper installation of lag The lag screws or bolts shall be placed as shown in screws or bolts shall be verified by the authority having Figure 19. The lag screws or bolts shall be staggered jurisdiction. from the top to the bottom along the horizontal run of Figure 19. Ledger Board Fastener Spacing and Clearances. Through-Bolts manufacturerâ€™s recommendations. All anchors must have Through-bolts shall have a diameter of Â½". Pilot holes washers. for through-bolts shall be 17/ 9 32" to /16" in diameter. Through-bolts require washers at the bolt head and nut. Lag Screws Lag screws shall have a diameter of Â½" (see MINIMUM Expansion and Adhesive Anchors REQUIREMENTS). Lag screws may be used only when Use approved expansion or adhesive anchors when the field conditions conform to those shown in Figure attaching a ledger board to a concrete or solid masonry 14. See Figure 20 for lag screw length and shank wall as shown in Figure 15. Expansion and adhesive requirements. All lag screws shall be installed with anchor bolts shall have a diameter of Â½". Minimum washers. spacing and embedment length shall be per the Figure 20. Lag Screw Requirements. Lag screw installation requirements: Each lag screw SCREWS WITH A HAMMER. Use soap or a wood- shall have pilot holes drilled as follows: 1) Drill a Â½" compatible lubricant as required to facilitate tightening. diameter hole in the ledger board, 2) Drill a 5/ Each lag screw shall be thoroughly tightened (snug but 16" diameter hole into the band board of the house. DO NOT not over-tightened to avoid wood damage). DRILL A Â½" DIAMETER HOLE INTO THE BAND JOIST. The threaded portion of the lag screw shall be inserted into the pilot hole by turning. DO NOT DRIVE LAG American Wood Council PRESCRIPTIVE RESIDENTIAL WOOD DECK CONSTRUCTION GUIDE 17 NON-LEDGER DECKS - FOR RESISTING FOOTINGS SHALL BE PLACED AT THE SAME VERTICAL LOADS ELEVATION AS THE HOUSE FOOTING IF LOCATED CLOSER THAN 5'-0" TO A HOUSE Non-ledger decks use the house for resisting lateral loads WALL (see Figure 2 and Figure 12). For houses with but do not utilize the exterior wall of the house to basements, a cylindrical footing (caisson) is support vertical loads (see Figure 21). Rather than recommended to minimize required excavation at the supporting the deck on a ledger, an additional beam with basement wall. Beam size is determined by Table 3. posts is provided at or within the lesser of LO or L/4 of Non-ledger decks shall be attached to the house per the house. THE ASSOCIATED DECK POST Table 5 and Figures 22 or 23 for lateral loads. Figure 21. Non-Ledger Deck - For Resisting Vertical Loads. DECK LATERAL LOADS For non-ledger decks, blocking or framing angles can be used in lieu of joist hangers and shall be provided on Attachment to House: Decks shall be positively each side of each joist. Blocking shall be installed with anchored to the primary structure [R507.1]. The lateral 5-10d threaded nails into the rim joist or the framing connection required shall be permitted to be in angle shall have a lateral capacity of 600 lb. Flashing accordance with Figure 22 or 23 for ledger and non- over the rim joist is required and must be installed in ledger decks. Hold-down tension devices shall be accordance with the flashing provisions in the LEDGER provided in not less than two locations within two feet of ATTACHMENT REQUIREMENTS. the edge of the deck, and shall have an allowable stress design capacity of not less than 1,500 lb [R507.2.4]. The wall must be sheathed with minimum 3/ 8" wood structural panel sheathing. Use lag screws or through- bolts when fastening to a band joist; use expansion anchors or epoxy anchors when fastening to concrete or masonry. DO NOT ATTACH TO BRICK VENEERS. VERIFY THIS CONDITION IN THE FIELD PRIOR TO UTILIZING THIS METHOD. Fasteners shall penetrate beyond the house band board and be installed per Table 5. American Wood Council 18 PRESCRIPTIVE RESIDENTIAL WOOD DECK CONSTRUCTION GUIDE Figure 22. Lateral Load Device with Floor Joists Parallel to Deck Joists. Figure 23. Lateral Load Device with Floor Joists Perpendicular to Deck Joists. American Wood Council PRESCRIPTIVE RESIDENTIAL WOOD DECK CONSTRUCTION GUIDE 19 GUARD REQUIREMENTS construction when approved by the authority having jurisdiction. All decks greater than 30" above grade are required to have a guard [R312.1] - one example is shown in Figure 24. Other methods and materials may be used for guard Figure 24. Example Guard Detail. GUARD POST ATTACHMENTS FOR REQUIRED Figure 25. Guard posts for required guards that run GUARDS perpendicular to the deck joists shall be attached to the rim joist in accordance with Figure 26. Only hold-down Deck guard posts for required guards shall be a anchor models meeting these minimum requirements minimum 4x4 (nominal) with an adjusted bending shall be used. Hold-down anchors shall have a minimum design value not less than 1,100 psi. Joists and rim joists allowable tension load of 1,800 pounds for a 36" to which guard posts are attached shall be a minimum of maximum guard height and be installed in accordance 2x8 (nominal). with the manufacturerâ€™s instructions. Guard posts for required guards which run parallel to the deck joists shall be attached to the outside joist per Figure 25. Guard Post to Outside-Joist Example. American Wood Council 20 PRESCRIPTIVE RESIDENTIAL WOOD DECK CONSTRUCTION GUIDE Figure 26. Guard Post to Rim Joist Example. STAIR REQUIREMENTS Figure 27. Tread and Riser Detail. Stairs, stair stringers, and stair guards shall meet the requirements shown in Figure 27 through Figure 34 and Table 6 except where amended by the local jurisdiction. All stringers shall be a minimum of 2x12. Stair stringers shall not span more than the dimensions shown in Figure 28. If the stringer span exceeds these dimensions, then a 4x4 post may be provided to support the stringer and shorten its span length. The 4x4 post shall be notched and bolted to the stringer with (2) Â½" diameter through- bolts with washers per Figure 8A. The post shall be centered on a 12" diameter or 10" square, 6" thick footing. The footing shall be constructed as shown in Figure 34 and attached to the post as shown in Figure 12. An intermediate landing may also be provided to shorten the stringer span (see provisions below). If the total vertical height of a stairway exceeds 12'-0", then an intermediate landing shall be required. All intermediate stair landings must be designed and constructed as a non-ledger deck using the details in this document. Stairs shall be a minimum of 36" in width as shown in Figure 33 [R311.7]. If only cut stringers are used, a minimum of three are required. For stairs greater than 36" in width, a combination of cut and solid stringers can be used, but shall be placed at a maximum spacing of 18" on center (see Figure 29). The width of each landing shall not be less than the width of the stairway served. Every rectangular landing shall have a minimum dimension of 36" measured in the direction of travel and no less than the width of the stairway served [R311.7]. American Wood Council PRESCRIPTIVE RESIDENTIAL WOOD DECK CONSTRUCTION GUIDE 21 Figure 28. Stair Stringer Requirements. Figure 29. Tread Connection Requirements. Figure 30. Stair Guard Requirements. Figure 31. Stair Stringer Attachment Detail. Table 6. Minimum Tread Size for Cut and Solid Stringers.1 Cut Solid Species Stringer Stringer Southern Pine 2x4 or 5/4 2x8 Douglas Fir Larch, Hem-Fir, SPF2 2x4 or 5/4 2x8 or 3x4 Redwood, Western Cedars, Ponderosa Pine,3 Red Pine3 2x4 or 5/4 2x10 or 3x4 1. Assumes 300 lb concentrated load, L/288 deflection limit, No. 2 stress grade, and wet service conditions. 2. Incising assumed for Douglas Fir-Larch, Hem-Fir, and Spruce- Pine-Fir. 3. Design values based on northern species with no incising assumed. American Wood Council 22 PRESCRIPTIVE RESIDENTIAL WOOD DECK CONSTRUCTION GUIDE STAIR HANDRAIL REQUIREMENTS STAIR FOOTING REQUIREMENTS [R403] All stairs with 4 or more risers shall have a handrail on Where the stairway meets grade, attach the stringers to at least one side (see Figure 32A) [R311.7.8]. The the stair guard posts as shown in Figure 34. Posts shall handrail height measured vertically from the sloped bear on footings. All footings shall bear on solid ground plane adjoining the tread nosing shall be not less than 34 and shall be placed at least 12 inches below the inches and not more than 38 inches (see Figure 30) undisturbed ground surface or below the frost line, [R311.7.8.1]. Handrails shall be graspable and shall be whichever is deeper (see Figure 34). Stringers shall bear composed of decay-resistant and/or corrosion resistant on a 2x4 bearing block attached to the post as shown. material. Handrails shall be Type I, Type II, or provide Stringers shall not bear on new or existing concrete pads equivalent graspability (see Figure 32B). Type I shall or patios that are not founded below this depth. When have a perimeter dimension of at least 4" and not greater guards are not required (see GUARD than 6-Â¼". Type II rails with a perimeter greater than REQUIREMENTS), posts may terminate below the 6-Â¼" shall provide a graspable finger recess area on both bottom tread elevation. Bolts are only required if a guard sides of the profile [R311.7.8.3]. All shapes shall have a post is required. smooth surface with no sharp corners. Handrails shall STAIR LIGHTING REQUIREMENTS [R303.7] run continuously from a point directly over the lowest riser to a point directly over the highest riser and shall Stairways shall have a light source located at the top return to the guard at each end (see Figure 33). Handrails landing such that all stairs and landings are illuminated. may be interrupted by guard posts at a turn in the stair The light switch shall be operated from inside the house. [R311.7.8.2]. However, motion detected or timed switches are acceptable. Figure 33. Miscellaneous Stair Requirements. Figure 32A. Handrail Mounting Examples. Figure 32B. Handrail Grip Size. Figure 34. Stair Footing Detail. American Wood Council PRESCRIPTIVE RESIDENTIAL WOOD DECK CONSTRUCTION GUIDE 23 FRAMING AT CHIMNEY OR BAY WINDOW shown in Figure 1B. Joist hangers shall each have a minimum vertical capacity in accordance with Table 7. All members at a chimney or bay window shall be Bolts, screws, or lag screws used to attach the hanger to framed in accordance with Figure 35. Headers may span the ledger shall fully extend through the ledger into the a maximum of 6'-0". When a chimney or bay window is 2-inch nominal lumber band joist (1-Â½" actual) or LVL wider than 6'-0", one or more 6x6 posts may be added to rim joist. Otherwise a non-ledger deck is required. reduce header spans to less than 6'-0". In such cases, the post footing must meet the requirements in the FOOTINGS section. Headers shall be located no more Table 7. Trimmer Joist Hanger Vertical Capacity. than 3'-0" from the end of the trimmer joist. Joist Size Minimum Capacity, lbs Triple trimmer joists are required on each side of the 2x6 870 header if joist spacing is 12" or 16" o.c. or if the trimmer joist span exceeds 8'-6"; otherwise, double trimmer joists 2x8 1155 are permitted. Trimmer joists may bear on the beam and 2x10 1420 extend past the beam centerline up to the lesser of LO or L/4 as shown in Figures 1A and 2, or the trimmer joist 2x12 1575 may attach to the side of the beam with joist hangers as Figure 35. Detail for Framing Around a Chimney or Bay Window. American Wood Council 24 PRESCRIPTIVE RESIDENTIAL WOOD DECK CONSTRUCTION GUIDE REFERENCES 2015 International Residential Code (IRC), International ASTM Standard B 695-04, Standard Specification for Code Council (ICC), Washington, DC, 2015. Coatings of Zinc Mechanically Deposited on Iron and Steel, ASTM, West Conshohocken, PA 2016. ANSI/ASME Standard B18.2.1-2010, Square, Hex, Heavy Hex, and Askew Head Bolts and Hex, Heavy Hex, ASTM F 1667-17, Standard Specification for Driven Hex Flange, Lobed Head, and Lag Screws (Inch Series), Fasteners: Nails, Spikes, and Staples, ASTM, West American Society of Mechanical Engineers, New York, Conshohocken, PA 2017. NY, 2010. Attachment of Residential Deck Ledger to Metal Plate ANSI/ASME Standard B18.6.1-1981 (Reaffirmed 1997), Connected Wood Truss Floor System, Structural Wood Screws (Inch Series), American Society of Building Components Association (SBCA), Mechanical Engineers, New York, NY, 1982. www.sbcindustry.com, 2015. ASTM A 123-17, Specification for Zinc (Hot-Dip AWPA Book of Standards, American Wood Protection Galvanized) Coatings on Iron and Steel Products, Association, Birmingham, AL, 2017. ASTM, West Conshohocken, PA 2017. Policy for Evaluation of Recommended Spans for Span ASTM Standard A 153-16a, Standard Specification for Rated Decking Products, American Lumber Standard Zinc Coating (Hot-Dip) on Iron and Steel Hardware, Committee, Germantown, MD 2004. ASTM, West Conshohocken, PA 2016. ASTM A 653-17, Standard Specification for Steel Sheet, Zinc-Coated (Galvanized) or Zinc-Iron Alloy-Coated (Galvannealed) by the Hot-Dip Process, ASTM, West Conshohocken, PA 2017. It is intended that this document be used in conjunction with competent design, accurate fabrication, and adequate supervision of construction. While every effort has been made to insure the accuracy of the information presented, the American Wood Council and its members do not assume responsibility for errors or omissions in the document, nor for designs, plans, or construction prepared from it. Those using this document assume all liability arising from its use. Copyright Â© 2007, 2009, 2010, 2014, 2015, 2018 American Wood Council 04-18 American Wood Council Prescriptive Residential Wood Deck Construction Guide â€“ Appendix A1 Appendix A to Prescriptive Residential Wood Deck Construction Guide DCA 6 SAFETY GLAZING REQUIREMENTS: IRC Exceptions to this requirement include: R308.4 states that safety glazing in window glass is required when the existing house wall acts as a barrier to - When a protective bar is installed on the accessible adjacent stairs, landings, and areas at the top and bottom side(s) of the glazing 36" Â± 2" above the deck of stairs. If a window or portion thereof falls within the surface. The bar shall be capable of withstanding a area shown in Figure A1, glass panes within that area horizontal load of 50 plf without contacting the glass should be safety glazed. Safety glazing should reduce and be a minimum of 1-Â½" in height. injury due to accidental impact when ascending or - The side of a stairway, landing, or ramp has a descending stairs. Application of safety glazing film to guardrail or handrail, including balusters or in-fill glass that was not originally treated is acceptable to meet panels, complying with the provisions of Sections this requirement. R311.7.8 and R312 and the plane of the glass is more than 18" from the railing. - When a solid wall or panel extends from the plane of the adjacent walking surface to 34" - 36" above the floor and the construction at the top of that wall or panel is capable of withstanding the same horizontal load as the protective bar. 36" glass in windows within this area adjacent stairs must be safety glazed 60" 60" 60" Figure A1. Safety glazing requirements. American Wood Council Prescriptive Residential Wood Deck Construction Guide â€“ Appendix B1 Figure B1. Examples of Tributary Areas Appendix B to Prescriptive Residential Wood Deck Construction Guide DCA 6 This Appendix to DCA 6 â€“ Prescriptive Residential Wood Deck Construction Guide has been requested by builders, building officials, and others, to provide an alternative to the assumptions of Table 4 Post Height for 6x6 and Footings Sizes for all Posts. DCA 6 is written to be as simple and easy to use as possible; however, this means that conservative assumptions often have to be made. This is especially true for Table 4, which assumes Joist Length, JL full cantilevers on both the joist and the beam. If full The joist length is defined differently for this appendix cantilevers are not present, the load will be less than than the main provisions of DCA 6. The joist length is assumed in Table 4, and the footing size will often not the design span of the joist, but is from the ledger decrease and allowable post height will often increase. face to either the center point of the beam, if there is an This Appendix is an aid to calculating the loads on posts overhang, or to the outside face of the rimboard if there and footings based on the actual deck configuration. is not an overhang. See Figure B2. Tributary Area Joist Overhang Length, JO Since uniform loading is prescriptively set for DCA 6, The length of the joist overhang is measure from the only the area the post or footing is supporting needs to outside edge of the deck to the centerline of the beam. be determined. This is called the tributary area and is See Figure B2. If no overhang exists, zero is entered into shown in Figure B1.Tributary area of a center or corner equation B-1 or B-2 for JO. post can be found from Figure B1 or by using the following formulas: Figure B2. Joist Length and Overhang 1 A ï€½ ( J ï€«J )(B ) Eq. B-1 Center Post 2 L O L 1 1 A ï€½ ( J ï€«J )( B ï€«B )Eq. B-2 Corner Post 2 L O 2 L O Where: A is tributary area (ft2) JL is length of joist (ft) JO is length of joist overhang (ft) BL is the length of the beam span (ft) BO is the length of the beam overhang (ft) American Wood Council B2 Prescriptive Residential Wood Deck Construction Guide â€“ Appendix Beam Span Length, BL Figure B3. Beam Span and Overhang Length The beam span is measured from either centerline of post to centerline of post, if there are overhangs, or to the outside edges of the deck, if there are no overhangs. For posts or footings being considered with two unequal, adjacent beam spans, the greater span shall be used. See Figure B3. Beam Overhang Length, BO The length of the beam overhang is measured from the outside edge of the deck to the centerline of the nearest post. See Figure B3. If a center post or footing is being considered or no overhang exists, zero is entered into the equation B-1 or B-2 for BO. Post and Footings Size As an alternative to Table 4 of DCA 6, the post height and footing size may be in accordance with Table B1 through B3. American Wood Council Prescriptive Residential Wood Deck Construction Guide â€“ Appendix B3 Table B1. Post Heights Based1,3 on Tributary Area for Corner Posts. 6x6 Post Height (ft.) 4x4 Post Height (ft.) 2 2 , , 2 2 2 2 (sq. ft.) Larch Larch Hem-Fir Redwood Hem-Fir Redwood Douglas Fir- Douglas Fir- Tributary Area Southern Pine Southern Pine Western Cedars Ponderosa Pine, Red Pine, SPF Western Cedars Ponderosa Pine, Red Pine, SPF 10 14 14 14 14 14 9 7 7 11 8 20 14 14 14 14 14 6 4 5 7 5 30 14 14 14 14 14 5 3 4 6 4 40 14 14 14 14 14 4 3 3 5 3 50 14 14 14 14 14 4 2 3 4 3 60 14 14 14 14 14 3 2 2 4 2 70 14 14 14 14 13 3 2 2 3 2 80 14 14 13 14 12 2 2 2 3 2 90 14 14 12 14 10 2 2 2 2 2 100 14 14 11 13 9 2 2 2 2 2 110 14 13 10 12 7 2 2 2 2 2 120 13 12 10 12 6 2 2 2 2 2 130 13 11 9 11 4 2 2 2 2 2 140 12 11 8 10 2 2 2 2 2 2 150 11 10 7 10 2 2 2 2 2 2 160 11 9 6 9 2 2 2 2 2 2 170 10 9 5 9 NP 2 2 2 2 2 180 10 8 3 9 NP 2 2 2 2 2 190 10 7 2 8 NP 2 2 2 2 2 200 8 7 2 8 NP 2 2 2 2 2 210 8 6 2 7 NP 2 2 2 2 2 220 7 5 2 7 NP 2 2 2 2 2 230 6 4 2 7 NP 2 2 2 2 2 240 6 2 2 6 NP 2 2 NP 2 2 250 5 2 2 6 NP 2 2 NP NP NP 1. Assumes No 2. Stress grade and wet service conditions. 2. Incising assumed for Douglas fir-larch, hem-fir, and spruce-pine-fir. 3. Some post heights for 4x4 post sizes show a greater load carrying capacity than 6x6 post sizes since different ASTM Standards are used to develop design values for visually graded dimension lumber vs. visually graded timbers. American Wood Council B4 Prescriptive Residential Wood Deck Construction Guide â€“ Appendix Table B2. Post Heights Based1,3 on Tributary Area for Center Posts. 6x6 Post Height (ft.) 4x4 Post Height (ft.) 4 2 2 , , 2 2 2 2 (sq. ft.) Larch Larch Hem-Fir Redwood Hem-Fir Redwood Douglas Fir- Douglas Fir- Tributary AreaSouthern Pine Western Cedars Ponderosa Pine, Red Pine, SPFSouthern Pine Western Cedars Ponderosa Pine, Red Pine, SPF 10 14 14 14 14 14 14 14 14 14 14 20 14 14 14 14 14 14 14 14 14 14 30 14 14 14 14 14 14 14 13 13 14 40 14 14 14 14 14 13 14 11 11 12 50 14 14 14 14 14 11 12 10 10 10 60 14 14 14 14 14 10 11 10 9 10 70 14 14 14 14 14 9 10 9 8 9 80 14 14 14 14 14 9 9 8 7 8 90 14 14 14 14 14 8 9 7 7 7 100 14 14 14 14 14 8 8 7 7 7 110 14 14 14 14 14 7 8 6 6 6 120 14 14 14 14 14 7 7 6 6 6 130 14 14 14 14 13 6 7 5 6 6 140 14 14 13 14 11 6 7 5 5 5 150 14 14 13 14 10 6 6 5 5 5 160 14 14 12 13 8 6 6 5 5 5 170 14 14 11 13 6 5 6 4 4 5 180 14 14 11 12 NP 5 6 4 4 4 190 13 13 11 12 NP 5 5 4 4 4 200 13 13 10 11 NP 4 5 3 4 4 210 12 12 8 11 NP 4 5 3 3 3 220 12 11 8 10 NP 4 5 2 3 3 230 11 11 7 10 NP 4 4 2 3 2 240 10 10 6 10 NP 3 4 NP 2 2 250 10 10 5 9 NP 3 4 NP 1 NP 1. Assumes No 2. Stress grade and wet service conditions. 2. Incising assumed for Douglas fir-larch, hem-fir, and spruce-pine-fir. 3. Some post heights for 4x4 post sizes show a greater load carrying capacity than 6x6 post sizes since different ASTM Standards are used to develop design values for visually graded dimension lumber vs. visually graded timbers. 4. Tributary area shall be multiplied by 1.25 at center posts with beams not spliced (continuous). American Wood Council Prescriptive Residential Wood Deck Construction Guide â€“ Appendix B5 Table B3. Footing Sizes1 Based on Tributary Area for Various Soil Capacities. Soil Bearing Capacity 1500 psf 2000 psf 2500 psf 3000 psf 2 (in.) (in.) (in.) (in.) (sq. ft.) Footing Footing Footing Footing Tributary AreaRound Footing Diameter (in.) Square Footing Thickness (in.) Round Footing Diameter (in.) Square Footing Thickness (in.) Round Footing Diameter (in.) Square Footing Thickness (in.) Round Footing Diameter (in.) Square Footing Thickness (in.) 10 8 7 6 7 7 6 7 6 6 6 5 6 20 12 10 6 10 9 6 9 8 6 8 7 6 30 14 13 6 12 11 6 11 10 6 10 9 6 40 16 15 6 14 13 6 13 11 6 12 10 6 50 18 16 7 16 14 6 14 13 6 13 12 6 60 20 18 8 17 15 6 16 14 6 14 13 6 70 22 19 9 19 17 7 17 15 6 15 14 6 80 23 21 9 20 18 8 18 16 7 16 15 6 90 25 22 10 21 19 8 19 17 7 17 15 6 100 26 23 11 23 20 9 20 18 8 18 16 7 110 28 25 12 24 21 10 21 19 8 19 17 7 120 29 26 12 25 22 10 22 19 9 20 18 8 130 30 27 13 26 23 11 23 20 9 21 18 8 140 31 28 13 27 24 11 24 21 10 22 19 9 150 33 29 14 28 25 12 25 22 10 22 20 9 160 34 30 15 29 25 12 25 23 10 23 20 9 170 35 31 15 30 26 13 26 23 11 24 21 10 180 36 32 16 30 27 13 27 24 11 24 22 10 190 37 33 16 31 28 13 28 25 12 25 22 10 200 38 34 17 32 29 14 28 25 12 26 23 11 210 39 35 17 33 29 14 29 26 12 26 23 11 220 40 35 18 34 30 15 30 26 13 27 24 11 230 41 36 18 35 31 15 31 27 13 28 25 12 240 42 37 19 35 31 15 31 28 13 28 25 12 250 43 38 19 36 32 16 32 28 14 29 26 12 1. Assumes 40 psf live load, 10 psf dead load, 150 pcf concrete and 2,500 psi compressive strength of concrete. Coordinate footing thickness with post base and anchor requirements. 2. Tributary area shall be multiplied by 1.25 at center posts with beams not spliced (continuous). American Wood Council Prescriptive Residential Wood Deck Construction Guide â€“ Commentary C1 Commentary to Prescriptive Residential Wood Deck Construction Guide DCA 6 Foreword This Commentary to DCA 6 â€“ Prescriptive Residential Wood Deck Construction Guide has been requested by builders, building officials, and others, to provide background information and example calculations for various sections and tables of DCA 6. The DCA 6 Commentary follows the same organization as DCA 6. Discussion of a particular provision in DCA 6 is found in the DCA 6 Commentary by locating the same section or subsection found in DCA 6. Not every section of DCA 6 has a corresponding commentary section. The DCA 6 Commentary provides background information intended to give the reader an understanding of the data Background and/or experience upon which the provision is based. In August 2006, AWC, then part of the American Forest One or more examples of the calculation procedures & Paper Association, formed an ad-hoc task group to used to produce several of the tables are given to address prescriptive provisions for residential wood deck illustrate the scope of conditions covered by the table. construction. Representatives of the wood products industry, home builders, connector manufacturers, The provisions of DCA 6 come primarily from the building officials, and truss industry were represented on International Code Councilâ€™s (ICC) International the task group. Residential Code (IRC). In developing the DCA 6 Commentary, data available from laboratory tests and The task group was assigned to review existing experience with structures in-service was analyzed and information to determine if there was something on evaluated for the purpose of providing a consistent which to build. One resource reviewed was a document explanation. It is intended that this document be used in developed by the Fairfax County, Virginia Department conjunction with competent design, accurate fabrication, of Public Works and Environmental Services titled and adequate supervision of construction. Therefore, the Typical Deck Details. With Fairfax Countyâ€™s permission, American Wood Council (AWC) does not assume any this became the basis for DCA 6. responsibility for errors or omissions in the DCA 6 Commentary, nor for designs or plans prepared from it. Since Fairfax Countyâ€™s Typical Deck Details was developed for a specific geographic location, DCA 6 was Inquiries, comments, and suggestions from readers of expanded to apply on a national basis (e.g. addition of this document are invited. western lumber species). The first version of DCA 6 was posted to the AWC website in October 2007. American Wood Council At the end of 2013 and into 2014, the task group was formed again to update DCA 6 to be in compliance with the 2012 IRC. DCA6-12 was posted on the AWC website in June 2014. DCA6 was updated based on the 2015 IRC and was posted in April 2018. Copyright Â© 2018 American Wood Council C2 Prescriptive Residential Wood Deck Construction Guide â€“ Commentary Basis intent of the provisions of this code, and that the As stated in the boxed text on the cover of DCA 6, material, method or work offered is, for the purpose provisions and details are based on the International intended, at least the equivalent of that prescribed in this Code Councilâ€™s International Residential Code. The code.â€ While AWC develops design tools and guidelines original version of DCA 6 was based on the 2006 IRC. for wood construction, it is recognized that decks are The current version of DCA 6 is based on the 2015 IRC. built with materials other than wood. Many of these materials undergo scrutiny through a code evaluation Alternative Methods and Materials process such as that promulgated by ICCâ€™s Evaluation A key point for users is the statement: â€œThis document is Services. Typically, the result is an Evaluation Service not intended to preclude the use of alternative methods Report (ESR) for the product. The building official is and materials.â€ Further, IRC R104.11 states: â€œAn usually the authority having jurisdiction and makes the alternative material, design or method of construction final decision regarding all construction methods and shall be approved where the building official finds that materials. the proposed design is satisfactory and complies with the MINIMUM REQUIREMENTS and LIMITATIONS include helical (spiral) and annular (ring-shank) nails as defined in ASTM F 547. Including the common terms 1. This document applies to single level residential wood â€œspiralâ€ and â€œring-shankâ€ is important to ensure decks only. Multiple level decks will likely have stairs availability from lumber yards. Reference design values that create additional concentrated loads that are not for post-frame ring shank nails in accordance with ASTM considered in the joist and beam span tables for DCA 6. F1667 are provided in the 2015 National Design Non-residential decks or balconies typically require design by a licensed professional. All decks prescribed SpecificationÂ® (NDSÂ®) for Wood Construction. in DCA 6 use the primary structure to resist lateral forces 6. NDS Chapter 11 contains spacing, end, and edge per Section R507.2.4 of the IRC. distance requirements for various fasteners, including bolts and lag screws. 2. This ratio is limited to 1:1, similar to open-front structures defined in Special Design Provisions for Wind 7. When subjected to standardized laboratory tests that and Seismic (SDPWS). Decks covered in this document accelerate the corrosion process, metal connectors and are assumed to be diaphragms that cantilever from the fasteners exposed to the chemicals used in certain house and are limited to a deck length-to-width ratio of preservative treatments exhibit high rates of corrosion. 1:1. Larger aspect ratios may be permitted where Users should rigorously apply recommendations of the calculations show that larger diaphragm deflections can chemical manufacturers and the treating industry â€“ to be tolerated. See Deck Framing Plan. use corrosion resistant fasteners and connectors or zinc coated (galvanized) fasteners and connectors with 3. DCA 6 provides 6x6 nominal posts as the primary corrosion protection at least equivalent to that of hot-dip prescriptive solution with the alternative to substitute galvanized products. Additional information is available 8x8 posts. In some instances, this commentary provides from various sources including: a 4x4 nominal post alternative. See commentary http://awc.org/faqs/general/where-can-i-find- regarding Table 4. information-about-corrosion-of-fasteners 4. Table 1 does not provide an exhaustive list of FEMA TB8-96, Technical Bulletin 8, Corrosion preservative treatments for ground contact lumber. The Protection of Metal Connectors in Coastal Areas, American Wood Protection Association (AWPA) recommends that stainless steel fasteners be used in promulgates voluntary wood preservation standards. areas exposed to salt water. AWPA Standards are developed by its technical committees under an ANSI accredited consensus-based 8. Concentrated loads, such as those created by hot tubs, process. Note also that many preservative treatments stairs, and planters, are beyond the scope of DCA 6. undergo scrutiny through a code evaluation process such as that promulgated by ICCâ€™s Evaluation Services. Typically, the result is an Evaluation Service Report 9. Structural members and connections shown in DCA 6 (ESR) for the product. have been sized based primarily on a uniformly distributed floor live load of 40 psf and a dead load of 10 5. Smooth shank nails are prone to â€œbacking outâ€ of psf (table footnotes specify where other point loads have wood due to moisture cycling. Deformed-shank nails been considered). If a deck is not prone to sliding or American Wood Council Prescriptive Residential Wood Deck Construction Guide â€“ Commentary C3 drifting snow, the criteria in DCA 6 can be wall or floor assembly of wood-frame construction.â€ conservatively applied to a deck with a uniformly Aluminum flashing should not be used if it will be in distributed snow load of 40 psf and a 10 psf dead load. contact with treated lumber. Lumber treated with certain preservatives contain copper and will corrode aluminum 10. Section R507.1 of the IRC states that decks shall be flashing as well as ferrous metals. designed to resist lateral loads and that the design is permitted to be per IRC Section 507.2.4. The IRC 12. IRC R110.1 Use and occupancy states: â€œA building currently does not state the design lateral loads for or structure shall not be used or occupiedâ€¦until the decks, but it does provide an approved design, which building official has issued a certificate of occupancyâ€¦â€ DCA 6 incorporates. 13. See Commentary for Alternative Methods and 11. IRC R703.4(5) requires attachment of flashing Materials. â€œâ€¦Where exterior porches, decks, or stairs attach to a DECKING REQUIREMENTS The American Lumber Standard Committee (ALSC) Load Conditions â€“ Allowable span analysis includes the Policy for Evaluation of Recommended Spans for Span following two load conditions with load applied on one Rated Decking Products (ALSC Decking Policy) span of a two-span continuous beam: provides a uniform method for assessing span-rated a. Uniform Load â€“ the calculated maximum decking products which are produced from many allowable fiber stress in bending derived from ASTM different species of wood, and graded under several D2555 and D245, or the In-grade test procedures of different grading standards. This ALSC policy covers ALSC Decking Policy, Annex 1 equals or exceeds specific products classified by size of decking and are the stress induced by a 70 psf uniform load on the assigned a recommended span of usually 16" or 24". recommended span. The analysis assumes normal This policy is not intended to be used for the assessment load duration. or approval of decking spans in excess of 24". The range b. Point Load â€“ the calculated maximum allowable of current grading rule specifications and species fiber stress in bending derived from ASTM D2555 requires the establishment of a uniform common and D245, or the In-grade test procedures of ALSC analytical procedure for assessing the appropriateness of Decking Policy, Annex 1 equals or exceeds the these products relative to the recommended spans. This stress induced by a 220 pound point load applied at ALSC policy establishes this uniform analytical the midpoint of one span. The analysis assumes 7- procedure. day load duration. The analysis for maximum span rating assumes the See Commentary for Alternative Methods and following design conditions: Materials for decking materials not covered by the 1. Span â€“ Two-span continuous with load applied to ALSC policy. In addition, alternate decking materials only one span. and/or use of alternate methods of fastening decking to 2. Seasoning â€“ Green use condition assumed to be joists has a critical impact on the resistance of lateral greater than 19%MC. loads. Equivalent strength and stiffness developed by 3. Deflection Limit â€“ Deflection under design loads alternative materials and fastening methods is important using calculated average allowable modulus of to ensure adequate lateral capacity. elasticity shall not exceed L/180. JOIST SIZE The format of Table 2 changed for DCA 6-15. An Span calculations in Table 2 assume a 40 psf live load, allowable simple span is given, and then an allowable 10 psf dead load, L/360 deflection limit for simple overhang for that span is calculated. The calculated spans, No. 2 grade lumber, and wet service conditions. allowable overhang is limited by the governing bending Overhang (cantilevers) calculations assume L/180 moment, deflection caused by the 220 lbs point load, or cantilever deflection with a 220 lbs point load (same as by a maximum cantilever span of one fourth of the back used for span rated decking), No. 2 grade lumber, and span (L/4). The 220 lbs point load always produces a wet service conditions. larger moment and deflection than the uniform load. See Table C2 which indicates where deflection controls American Wood Council C4 Prescriptive Residential Wood Deck Construction Guide â€“ Commentary overhang length. The new format was adopted in the Joist spans can cantilever past the joist bearing centerline 2018 IRC, so spans shown in DCA 6-15 are slightly up to LO or L/4 as shown in Figure 1A and Figure 2, or different than 2015 earlier versions of the IRC. the joists may attach to only one side of the beam with joist hangers as shown in Figures 1B. DCA 6 beam, Joist spans are based on lumber size and joist spacing. column, and footing tables assume that joists are only The span of a joist is measured from the face of bearing framed from one side of the beam, so allowing joists to at one end of the joist to the face of bearing at the other span from opposite sides of the beam without end of the joist and does not include the length of the appropriate design consideration could potentially lead overhangs. This method of measuring the â€œclearâ€ span is to a condition where beam, column, and footing for ease of construction and is commonly used by capacities are exceeded. builders; however, it differs from standard engineering practice, where span is defined as the distance between Incising factors are used for refractory species including centers of required bearing, as in the 2015 NDS. To align Douglas Fir-Larch, Hem-Fir, and Spruce-Pine-Fir. Hem- the two differing definitions, 3â€ was subtracted from Fir spans control for these three species combinations. each allowable span in Table 2 to account for the Ponderosa Pine and Red Pine were sized using Northern difference between tabulating clear span and engineered Species design values except that the incising factor was span. not applied since Ponderosa Pine and Red Pine are not incised when treated. Since incising is not necessary for Joist spans are limited to a maximum of 18'-0" to ensure naturally durable wood (heartwood of the following appropriate design of beams and footings. If longer joist species: decay-resistant Redwood and Cedars - corner spans are designed, joist hangers, beams, posts, and sapwood is permitted if 90 percent or more of the width footings will have to be analyzed to ensure appropriate of each side on which it occurs is heartwood), Redwood load path. See the span calculator at www.awc.org for and Western Cedar are also not incised. Since Ponderosa simple span conditions without overhangs, however Pine, Red Pine, Redwood, and Western Cedar have spans shall not exceed 18'-0" when used in conjunction comparable design values, Northern Species design with DCA 6. values are used to calculate the controlling spans for these four species combinations. Table C2. Conditions Where Deflection Controls Overhang Length*. Joist Spacing (o.c.) 12" 16" 24" Species Size Allowable Overhang3 (L O) 2x66 1' - 0" 1' - 1" 1' - 3" 2x8 1' - 10" 2' - 0" 2' - 4" Southern Pine 2x10 3' - 1" 3' - 5" 2' - 10" 2x12 4' - 6" 4' - 2" 3' - 4" 2x66 0' - 11" 1' - 0" 1' - 2" Douglas Fir- 2x8 1' - 8" 1' - 10" 2' - 2" Larch, Hem-Fir, 4 2x10 2' - 10" 3' - 2" 2' - 9" Spruce-Pine-Fir 2x12 4' - 4" 3' - 11" 3' - 3" Redwood, 2x66 0' - 9" 0' - 10" 0' - 11" Western Cedars, 2x8 1' - 5" 1' - 7" 1' - 9" Ponderosa Pine5, 2x10 2' - 5" 2' - 7" 2' - 8" Red Pine5 2x12 3' - 7" 3' - 9" 3' - 1" * Shading indicates overhang is deflection controlled. See Table 2 for footnotes. American Wood Council Prescriptive Residential Wood Deck Construction Guide â€“ Commentary C5 BEAM SIZE & ASSEMBLY REQUIREMENTS are lower than design values for these refractory species, Deck beam spans are in accordance with Table 3 and can the incising factors applied to strength and stiffness extend past the post centerline up to LB/4 as shown in values of refractory species offset the differences. Figure 3. Beams are sized based on reaction load from Therefore, span differences are minimal. Additionally, joists within the span limits shown in Table 2. Joists are Ponderosa Pine and Red Pine were sized using Northern assumed to span from one side only; therefore, joists Species design values except that the incising factor was shall not be attached to opposite sides of the same beam. not applied since Ponderosa Pine and Red Pine are not Allowing joists to span from opposite sides of the beam incised when treated. Therefore, design values for the without appropriate consideration could potentially lead Northern Species combination (includes Ponderosa Pine to a condition where beam capacity is exceeded. and Red Pine) are used to calculate spans for all of these species. With appropriate assumptions, Table 3 could be used to size beams with joists spanning from both sides. Since Glued laminated timber beams in deck applications are tabulated values for beams assume beams support clear required to be of naturally durable species or span joists with overhangs, using 2 times the joist span preservatively treated in accordance with AWPA U1. for cases where joists span symmetrically (equal joist When oil-borne preservatives are used, the glued spans) from opposite sides is acceptable. For example, laminated timber industry recommends that the NDS wet assume there are 8'-0" joists spanning from opposite service factor (CM) not be used in this specific outdoor sides of the same beam. The column in Table 3 labeled application; therefore, all glued laminated timber beams for 16'-0" joist spans can be used to size a beam in this have been designed using design values based on dry case. A similar procedure is required for designing service conditions. The adjustment factor of 0.89 in columns and footing sizes. Table 3B, footnote 1, is based on the square root of the wet service adjustment factor of 0.8 for bending design Douglas Fir-Larch, Hem-Fir and Spruce-Pine-Fir values as specified in the NDS Supplement for glued (refractory species) are combined with Redwood and laminated timber. Western Cedars (naturally durable species). Even though design values for these naturally durable species DECK FRAMING PLAN For resistance of lateral loads, the deck is assumed to act A framing plan shows the layout of the primary as a diaphragm in an open-front structure. The decking, structural system. Examples of structural elements when nailed to the joists and rim joist, acts as sheathing include: joists, beams, ledger board, posts, footings, in this diaphragm. stringers, treads, and the type, size, and spacing of ledger board fasteners. Figure C5 shows an example of a Larger aspect ratios may be permitted where calculations typical deck framing plan. show that larger diaphragm deflections can be tolerated. Copyright Â© 2018 American Wood Council C6 Prescriptive Residential Wood Deck Construction Guide â€“ Commentary Figure C5. Example of a Typical Deck Framing Plan. JOIST-TO-BEAM CONNECTION that an uplift load created by a 220 lbs point load at the Joist-to-beam connections must be installed to handle end of a cantilevered joist will be resisted. forces in several directions. Options 1 and 2 handle gravity loads through bearing of the joist to the beam, Connector manufacturers regard connectors with while Option 3 requires nails to resist these downward missing fasteners as improper installations and only loads. All three options have been evaluated to ensure support the product to be used with the type and number of fasteners specified in the product literature. JOIST HANGERS The loads listed in the Table 3A are derived from the Research has shown that joist hanger to ledger worst case condition for each joist size based on Table 2 connections resist lateral loads. When permitted by the (379 lbs, 483 lbs, 571 lbs, and 675 lbs for Southern Pine hanger manufacturer, the use of screws instead of nails joists spaced at 24" o.c. for 2x6, 2x8, 2x10, and 2x12, to attach hangers to the ledger can decrease the potential respectively). for the joist to pull away from the ledger. American Wood Council Prescriptive Residential Wood Deck Construction Guide â€“ Commentary C7 POST REQUIREMENTS IRC section R407.3 specifies a minimum 4x4 (nominal) The lateral force applied to corner posts is based on the wood column size; however, it would often be capacity of the connection at the brace. Therefore, the overstressed in applications covered in this document. full capacity of the brace connection is assumed to be Requiring a minimum 6x6 post in DCA 6 provides developed and applied 2 feet below the beam. adequate bearing for beams. If posts are intended to resist lateral load conditions, then posts need to be Table C4A. No. 2 Grade 4x4 Maximum Post Heights. designed per the NDS. An option of 8x8 nominal posts Post Heights1 allows for a deck height of up to 14' in all cases shown in Table 4 footnote 5. B J 2 Prohibiting attachment of the beam to the sides of the 2 post with fasteners only (Figure 9) ensures wood-to- , Western wood bearing. Design of fasteners for wet-service Pine 2 Larch Cedars conditions requires fairly significant capacity reductions Joist Span LSouthern Redwood Beam Span, L Douglas Fir- and should be evaluated by a design professional. Red Pine, SPF Ponderosa Pine, Hem-Fir For 3-ply 2-inch nominal beams, a post cap is required <10' 4' 2' 3' 4' 3' since the remaining cross section at the post notch would 6' <14' 3' 2' 2' 3' 2' not be sufficient to provide adequate connection of the <18' 2' 2' 2' 2' 2' beam to the column. The connector shown in Figure 8B <10' 3' 2' 2' 4' 2' is readily available with corrosion protection and offers 8' <14' 2' 2' 2' 3' 2' uplift and lateral load resistance. <18' 2' 2' 2' 2' 2' Provisions for Alternative Methods and Materials <10' 3' 2' 2' 3' 2' allow for other post sizes and post-to-beam connections 10' <14' 2' 2' 2' 2' 2' if approved by the building official. For example, in <18' 2' 2' 2' 2' 2' order to use a 4x4 post, a post cap connection as shown <10' 2' 2' 2' 2' 2' in Figure 8B would be required. There is not enough 12' <14' 2' 2' 2' 2' 2' cross sectional area in a 4x4 to permit the let-in notch <18' 2' 2' 2' 2' 2' detail as shown in Figure 8A. Connector hardware for a <10' 2' 2' 2' 2' 2' 4x4 post is generally limited to support of 2-ply 2 inch 14' <14' 2' 2' 2' 2' 2' nominal or 4 inch nominal beams. Certain post caps may <18' 2' 2' 2' 2' NP be adjusted to fit a 3-ply 2 inch nominal member onto a <10' 2' 2' 2' 2' 2' 4x4 post, but must be special ordered. Contact a 16' <14' 2' 2' 2' 2' 2' connector manufacturer to determine if there are <18' 2' 2' 2' 2' NP solutions for connecting a single 3 inch nominal member <10' 2' 2' 2' 2' 2' onto a 4x4 post. See Table C4A: 4x4 Post Heights. 18' <14' 2' 2' 2' 2' NP <18' 2' 2' NP 2' NP Diagonal bracing can contribute to the stiffness of the deck and, therefore, cause additional lateral loads on the 1. Assumes 40 psf live load, 10 psf dead load, LB/4 and LJ/4 posts. Since center posts receive more vertical load than overhangs, No 2. grade and wet service conditions. corner posts, additional lateral load can cause overstress. 2. Incising assumed for Douglas Fir-Larch, Hem-Fir, and Spruce-Pine- For this reason, Figure 10 does not show the use of Fir. diagonal bracing on center posts. FOOTINGS for the footing size an iterative process. The following Footing sizes are based on the assumptions of 1,500 psf equations may be used to size footings for other soil bearing capacity and 2,500 psi compressive strength assumptions (see Figure C12): of concrete which are the minimum values based on IRC Tables R401.4.1 and R402.2. See Table C4B for footing sizes with higher soil bearing capacities. A concrete weight of 150 pcf is also assumed, which makes solving American Wood Council C8 Prescriptive Residential Wood Deck Construction Guide â€“ Commentary Post load (lbs): Figure C12. Footing Dimensions and Variables. ïƒ¦ L ïƒ¶ B2T R ï€½ 50ïƒ§ Joist ï€« L ïƒ·ï€¨ï€©L ï€«150 ïƒ¨ 2 Joist Overhang ïƒ¸ Beam 1728 R or 2 ïƒ¦ LJoist ïƒ¶ Ï€D T 5.5? " P R ï€½ 50ïƒ§ ï€« LJoist Overhang ïƒ·ï€¨ï€©LBeam ï€«150 ïƒ¨ 2 ïƒ¸ 6912 where: L units are in feet and B, D, and T are in inches. T R Square footing (in.): Bï€½12 ï€¨ï€©soil capacity B or D 4R Round footing (in.): D ï€½12 ï€¨ï€©soil capacity Ï€ (B or D)ï€5.5 Footing thickness (in.): T > P; T ï‚³ 2 Table C4B. Footing Sizes for Higher Soil Bearing Capacities. 2000 psf 2500 psf 3000 psf B J Joist Span LDiameter Footing Thickness Diameter Footing Thickness Diameter Footing Thickness Beam Span, L Round Footing Square Footing Round Footing Square Footing Round Footing Square Footing â‰¤10' 15" 13"x13" 6" 14" 12"x12" 6" 12" 11"x11" 6" 6' â‰¤14' 18" 16"x16" 7" 16" 14"x14" 6" 15" 13"x13" 6" â‰¤18' 20" 18"x18" 8" 18" 16"x16" 7" 16" 15"x15" 6" â‰¤10' 17" 15"x15" 6" 16" 14"x14" 6" 14" 13"x13" 6" 8' â‰¤14' 21" 18"x18" 8" 18" 16"x16" 7" 17" 15"x15" 6" â‰¤18' 23" 21"x21" 9" 21" 18"x18" 8" 19" 17"x17" 7" â‰¤10' 19" 17"x17" 7" 17" 15"x15" 6" 16" 14"x14" 6" 10' â‰¤14' 22" 21"x21" 9" 20" 18"x18" 8" 19" 17"x17" 7" â‰¤18' 26" 23"x23" 11" 23" 21"x21" 9" 21" 19"x19" 8" â‰¤10' 21" 19"x19" 8" 19" 17"x17" 7" 17" 15"x15" 6" 12' â‰¤14' 25" 22"x22" 10" 22" 20"x20" 9" 20" 18"x18" 8" â‰¤18' 29" 26"x26" 12" 26" 23"x23" 11" 23" 21"x21" 9" â‰¤10' 23" 21"x21" 9" 20" 18"x18" 8" 19" 17"x17" 7" 14' â‰¤14' 27" 24"x24" 11" 24" 22"x22" 10" 22" 20"x20" 9" â‰¤18' 31" 28"x28" 13" 28" 24"x24" 12" 25" 22"x22" 10" â‰¤10' 25" 22"x22" 10" 22" 19"x19" 9" 20" 18"x18" 8" 16' â‰¤14' 29" 26"x26" 12" 26" 23"x23" 11" 24" 21"x21" 10" â‰¤18' 33" 30"x30" 14" 30" 26"x26" 13" 27" 24"x24" 11" â‰¤10' 26" 23"x23" 11" 23" 21"x21" 9" 21" 19"x19" 8" 18' â‰¤14' 31" 28"x28" 13" 28" 24"x24" 12" 25" 22"x22" 10" â‰¤18' 36" 32"x32" 16" 31" 28"x28" 13" 28" 25"x25" 12" American Wood Council Prescriptive Residential Wood Deck Construction Guide â€“ Commentary C9 Footnote 2 of Table 4 allows for the footing thickness Additional footing options were added to the 2012 and size to be reduced for corner posts since the version of DCA 6 Figure 12. One allows for a 12â€ tabulated values assume center posts, which resist more diameter concrete stem to reduce the amount of concrete vertical load. The factor is 0.9 because of additional load required. The second provides an option for a fully applied from the diagonal (knee) brace. embedded post in concrete with a gravel base to allow for water drainage. However, note that when the Coordinating the footing thickness with post base and embedded post option is used to resist lateral loads, the anchor requirements means ensuring that post anchor post must be designed per the NDS. length does not exceed the thickness of the footing. LEDGER ATTACHMENT REQUIREMENTS perpendicular to grain stresses if the outer edges of the Fastener spacing requirements in Table 5 are based on ledger are constrained by bolts. 2015 IRC R507.2.1, which is based on testing at Virginia Tech and Washington State University (Carradine et al., The requirement for minimum distance between the top 2006). Testing was conducted for three common deck of the ledger and the bottom row of fasteners (Figure 19) ledger constructions using Â½" diameter lag screws and is based on NDS 3.4.3.3(a) for shear design at bolts. In the tests, two types of band joist materials were connections. When the connection is less than five times used: 2x10 Spruce-Pine-Fir (SPF) lumber and 1-inch- the depth, 5d, of the bending member from its end, the thick Douglas-Fir (DF) laminated veneer lumber (LVL) adjusted design shear is calculated as follows: rim board. SPF has a relatively low specific gravity of G = 0.42, so other denser species groupings (e.g., Hem-Fir, Douglas-Fir-Larch, and Southern Pine) can be conservatively substituted. Thicker LVL products with Solving for de yields the following: equivalent specific gravities of 0.50 or greater can be conservatively substituted for the LVL band joist 3 2 de = 3 Vr d / (2 F'v b) material tested. In addition, manufactures of EWP rim boards may publish capacity and spacing requirement Assuming a Hem-Fir No. 2 ledger, the reference for their rim boards that can be used when designing horizontal shear design value, Fv = 150 psi. The adjusted attachment of ledgers to rim boards. shear design value, F'v, is based on a wet service factor, CM = 0.97, and incising factor, Ci = 0.80. The maximum According to IRC R311.3.1, the distance from the top of allowable lateral design value of 725 lbs for Â½" bolts and the threshold to the top of deck boards cannot exceed 385 lbs for Â½" lag screws - is based on testing at 1Â½". If a door does not swing over the landing or deck, Virginia Tech and Washington State University the step-down can be up to 7Â¾". The ledger can be (Carradine et al., 2006). Spacing calculations assume lowered for improved drainage, subject to meeting that bolts or lag screws at the end of the ledger have half maximum step-down heights for accessibility and means the tributary area of interior bolts or lag screws and that of egress, edge distance and spacing requirements, and the shear at interior bolts or lag screws is half of the shear design at connection requirements of NDS interior bolt or lag screw reaction. Therefore, the 3.4.3.3(a). minimum value of de is calculated assuming Vr equals one-half of the allowable lateral design value for the Â½" The basis for edge distances and spacing between rows bolts (725/2 lbs) or Â½" lag screws (385/2 lbs). Resulting (Figure 19) is NDS Tables 11.5.1C and 11.5.1D, values of de are as follows: respectively, for perpendicular to grain conditions. Per Â½" bolts Â½" lags NDS Table 11.5.1C, edge distance is 4D (where D is 2x8 de = 5.47" de = 4.43" fastener diameter) for the loaded edge. For Â½" diameter 2x10 de = 6.43" de = 5.21" bolts, 4D = 2" edge distance. 2x12 de = 7.33" de = 5.9" Per NDS Table 11.5.1D, spacing between rows is based The problem with these effective depths is that a 2x8 on the l /d ratio of the fastener. For a 1Â½" ledger and rim ledger connected to a 2x8 band joist with bolts will not board, l /d = 1Â½" / Â½" = 3 and the minimum spacing is work (see Figure C19). (5l + 10D) / 8 = 19/ 5 16" â€“ this is rounded up to 1 /8". Per 11.5.1.3 of the NDS, the maximum spacing between Possible solutions for the 2x8 band joist include: fasteners is 5". This requirement is based on potential 1) Non-ledger deck. shrinkage of the ledger which could create tension American Wood Council C10 Prescriptive Residential Wood Deck Construction Guide â€“ Commentary 2) Require lag screws for 2x8 band joist and revise Continuous flashing is required as shown in Figure 14 to required de = 4Â½" as shown in Figure 19. prevent water intrusion behind the ledger. One 3) Allow bolted connections for 2x8 band joist if alternative to this detail would be continuous flashing bolt spacing is reduced to the same as that for with a drip edge; however, this would be labor intensive lag screws (only applies to Â½" bolts without because the flashing would require notching at every stacked washers as shown in Table C5) as deck joist location. shown in Figure 19. 4) Reduce bolt spacing requirements for 2x8 ledger Connection of ledgers to existing empty or hollow to 2x8 band joist. When de = 4.5", Vr = 202 lbs, masonry cell blocks (Figure 15) is generally not practical and the back-calculated adjustment factor is because most manufacturers of concrete block anchors 0.56. Based on Table 2, the maximum joist span do not publish allowable shear values for a ledger for a 2x8 is 10'-6". This results in revised connected to empty hollow masonry block of unknown spacing for Â½" bolts as shown in Table C5. compression and breakout strength. Due to the uncertainty and lack of test data for this application, use To achieve the minimum spacing requirements noted of a non-ledger deck is recommended (see Figure 21). above, a nominal 2x8 ledger is required even if the deck joists are 2x6â€™s. Table C5. Revised Bolt Spacing Requirements for 2x8 Ledgers to 2x8 Band Joists. Joist Span 6'-0" & 6'-1" to 8'-1" to 10'-1" to less 8'-0" 10'-0" 12'-0" Â½" bolt 32" 24" 19" 16" Â½" bolt with Â½" 27" 20" 16" 13" stacked washers Figure C19. Edge Distance and Spacing Requirements for 2x8 Band Joist and 2x8 Ledger. NON-LEDGER DECKS â€” FOR RESISTING the primary structure but still relies on the primary VERTICAL LOADS structure to resist lateral loads; whereas, a free-standing The provisions of DCA 6 assume that the primary deck is both vertically and laterally independent. structure is used for lateral stability. A non-ledger deck, as defined in this document, is vertically independent of DECK LATERAL LOADS tension devices are still shown in DCA 6. In lieu of the Item 10 of DCA 6 Minimum Requirements & prescriptive hold-down tension devices specified, an Limitations states that the document does not address alternate engineered or approved connection detail lateral stability issues beyond those addressed in Section would be required. R507.2.4 of the IRC. Where deck joists are perpendicular to the house floor IRC R507.1 requires anchorage of the deck to the joists, blocking between house joists and boundary primary structure to resist lateral loads. Further, the IRC nailing of the house floor diaphragm to the blocking is includes hold-down tension devices as a prescriptive required for the installation of hold-down tension means to achieve compliance with the lateral load devices. connection requirements without requiring engineering. See IRC Section R507.2.4. Figure R507.2.3(2) was For connecting the hold down tension devices to I-joists, added to the IRC in the 2015 edition, but equivalent a detail recommended by the Wood I-Joist Manufactures performance to the existing prescriptive solution has not Association and similar to Figure R507.2.3(1) of the been demonstrated. Consequently, two 1500 lbs capacity IRC, is provided. American Wood Council Prescriptive Residential Wood Deck Construction Guide â€“ Commentary C11 however, the IRC does not prescribe diagonal bracing. For non-ledger decks, Figures 22 and 23 prescribe three See Post Requirements for more on the implications of methods of transferring lateral loads from deck joists to diagonal bracing. the rim board: joist hangers (as shown), blocking, or use of framing angles. This connection is to transfer forces Figures 22 and 23 show nailing from above through acting parallel to the house. A connection equal to the floor sheathing and into floor joists or blocking between diaphragm capacity of single layer diagonal boards, or floor joists of the house. An equivalent connection from approximately 300 plf, is required. underneath is permissible using framing angles and short fasteners to penetrate into the floor sheathing. Diagonal (knee) bracing is commonly used on decks to help resist lateral forces and provide increased stiffness; GUARD REQUIREMENTS exposure to falls over the top of the guard due to Figure 24 requires that openings not allow the passage of individuals standing on deck seats. a 4" diameter sphere. However, it does not address openings underneath a fixed deck bench used in place of IRC Table R301.5 requires guard in-fill components (all guards. All openings, including those underneath those except the handrail), balusters, and panel fillers to benches used in place of guards, shall not allow the be designed to withstand a horizontally applied normal passage of a 4" diameter sphere. load of 50 pounds on an area equal to 1 square foot. This load need not be assumed to act concurrently with any Additionally, if fixed seating is adjacent to guards, the other live load requirement. Baluster connection guard height should be measured from the seat rather requirements shown in Figure 24 have been designed to than the deck surface. While 2015 IRC Section R312.1.2 resist that load. allows for the guard height to be measured from the walking surface, DCA 6 requires measurement from fixed seating as a best practice. This will help minimize GUARD POST ATTACHMENTS FOR REQUIRED This section requires deck guard posts to be at least 4x4 GUARDS nominal with a reference bending design value not less Both the IRC and International Building Code (IBC) than 1,100 psi to ensure sufficient bending stress in the specify that guardrails and handrails be capable of post. Assuming the lever arm is 39.5" (36" + 1Â½" deck resisting a minimum concentrated live load of 200 lbs board + 2" edge distance), the bending moment is 39.5" applied in any direction for required guard rails (See IRC x 200 lbs = 7,900 in-lbs. Bending stress, f , is calculated b R312.1). Commonly used residential guardrail post as follows: connections were laboratory tested at the required load M/S 3 level for a code-conforming assembly per the IBC (4x4) = 7,900 in-lbs / 7.146 in = 1,106 psi. (Loferski et al., 2006). A commercially available connector, typically used in shear wall construction, was No. 2 grades of all Table 2 species meet this requirement tested in a post-to-deck residential guardrail assembly. with the following assumptions. The adjusted bending The connection passed a load test based on code design value, F'b, is based on a wet service factor, CM = provisions for a â€œtested assembly.â€ Connection details in 0.85, and incising factor, Ci = 0.80 (Douglas Fir-Larch, Figures 25 and 26 reflect these test results. Hem-Fir, Spruce-Pine-Fir). A load duration factor, CD = 1.6, is assumed for consistency with the hold-down A minimum requirement of 1,800 lbs for the hold-down device used to connect the guard to the joist. connector ensures adequate capacity (Loferski et al., 2005) for a 36" maximum rail height. A higher rail Figures 25 and 26 show minimum and maximum height requires design of a higher capacity connector. spacing requirements for bolts in deck joists and deck Manufacturersâ€™ tabulated values for hold-down rim boards. The 5" maximum spacing is per NDS connectors typically include a load duration (CD) 11.5.1.3. This requirement is based on potential increase of 60% since connectors for shear walls are shrinkage of the joist or rim board which could create used to resist wind and seismic loads. The 200 lbs tension perpendicular to grain stresses if the outer edges concentrated load requirement for guard rails is assumed of the deck joist or rim are constrained by bolts. To to be a 10 minute load duration (e.g. it would not see a achieve the minimum spacing requirements, a nominal maximum 200 lbs outward load for more than 10 2x8 or wider (deeper) outside joist or rim board is minutes cumulatively in its lifetime). Therefore, CD=1.6 required. is used for hold-downs in this application. American Wood Council Prescriptive Residential Wood Deck Construction Guide â€“ Commentary C12 STAIR REQUIREMENTS lbs is distributed across 2 inches (e.g. 150 pli), based on Figure 29 shows 5/4 boards spanning 18" or less. As L/288 deflection criteria (ICC ES Acceptance Criteria noted under DECKING REQUIREMENTS 174 requires 1/ 1 8" deflection limit: 36"/ /8" = 288). No commentary, specific products classified by size as species will calculate for that span using 2x6 No. 2 decking are usually assigned a recommended span of 16" grade. or 24". Solid stringers were analyzed as simple span beams Additionally, IRC Table R301.5 footnote (c) requires a using the horizontal span not the actual stringer length. 300 lbs concentrated load check on stair treads. Analysis Cut stringers were analyzed with 5.1" depth which is revealed that 2x8 No. 2 Southern Pine works for a 34Â½" based on 7.75:10 rise to run ratio. A size factor, CF, of span (36" minus Â¾" bearing at each end) when the 300 1.0 is used since 2x12 is the size basis. STAIR FOOTING REQUIREMENTS eleven #8 wood screws (16d box or common threaded Stair stringers should be supported by bearing at the end nails would be comparable). where the stairway meets grade. The detail shown assumes a 40 psf live load and 10 psf dead load over a While bolts are sometimes used for this detail, proximity tributary area of 18" and one-half of the maximum span to the end of the stringer could lead to splitting of the of 13'-3" permitted for solid stringers. This calculates to stringer â€“ especially cut stringers. The 2x4 bearing block 500 lbs. For Southern Pine, seven #8 wood screws alleviates this situation. However, in addition to the would be required. Northern Species would require bearing block, bolts would also be required to provide lateral support if a guard post is used. FRAMING AT CHIMNEY OR BAY WINDOW less than that shown in Table C7a, a double trimmer joist IRC R502.10 on framing of openings states: â€œOpenings is also permitted. in floor framing shall be framed with a header and trimmer joists. Where the header joist span does not Bending and shear were checked to determine the exceed 4 feet, the header joist may be a single member reduction in a double trimmer joist span when carrying a the same size as the floor joist. Single trimmer joists 6' header. For a simple span beam, with a concentrated shall be used to carry a single header joist that is located load offset from the center, maximum moment is within 3feet of the trimmer joist bearing. Where the calculated as Pab/LJ and maximum shear is calculated as header joist span exceeds 4 feet, the trimmer joists and Pb/LJ, where P is the concentrated load based on the the header joist shall be doubled and of sufficient cross tributary area carried by the header, b = LJ â€“ a, and LJ is section to support the floor joists framing into the the trimmer joist span. header.â€ Moment controlled for this analysis in determining amax. Trimmer Joist Size and Span Limited by Concentrated While shear was evaluated, the NDS permits the shear Load from the Header load to be reduced within a distance â€œdâ€ (equal to the Where the header frames into the trimmer joist, a joist depth) from the end of the joist. With that concentrated load is created. This condition was reduction, shear did not control any of the spans evaluated assuming one ply of a double trimmer joist evaluated. carries the uniform load and one ply carries the point load from a 6' header. The analysis revealed that the distance from the end of the trimmer joist to the point where the header frames into it â€“ designated as dimension â€œaâ€ â€“ must be limited. The maximum distance was calculated based on joist spans given in Table 2. A maximum distance of a = 3' was chosen to cover common framing conditions. Triple trimmer joists are required on each side of the header if joist spacing is 12" or 16" o.c., or if the trimmer joist span exceeds 8'-6"; otherwise a double trimmer joist is permitted. If â€œaâ€ is American Wood Council Prescriptive Residential Wood Deck Construction Guide â€“ Commentary C13 Table C7a. Maximum Distance â€œaâ€ from Trimmer Table C7b. Maximum Trimmer Joist Span (LJ) Based Joist End to a Point where a 6' Header Frames into on Distance â€œaâ€ from the Trimmer Joist End to the a 2-ply Trimmer Joist. 1,4 Point where the Header Frames into the Trimmer. Species Trimmer Size amax Ledger Species Size a = 1' a = 2' a = 3' 2-2x6 15" 2-2x8 17" 2x85 5' - 9" 7' - 5" 8' - 11" Southern Pine 2-2x10 19" Southern Pine 2x10 9' - 2" 10' - 11" 12' - 7" 2-2x12 25" 2x12 9' - 5" 11' - 2" 12' - 10" 2-2x6 11" Douglas Fir- 2x85 4' - 6" 6' - 0" 7' - 6" Douglas Fir-Larch, Hem- 2-2x8 14" Larch, Hem-Fir, 2x10 6' - 10" 8' - 6" 10' - 1" 2 Fir, SPF1 2-2x10 16" Spruce-Pine-Fir 2x12 7' - 0" 8' - 9" 10' - 4" 2-2x12 19" Ponderosa Pine3, 2x85 4' - 3" 5' - 9" 7' - 3" 2-2x6 10" Red Pine3, 2x10 6' - 5" 8' - 1" 9' - 8" Redwood, Western Redwood, 2-2x8 13" Cedars, Ponderosa Pine2, 2-2x10 16" Western Cedar 2x12 6' - 7" 8' - 3" 9' - 10" Red Pine2 1. Assumes 6' header span. See Figure 35 for header, trimmer, 2-2x12 18" and ledger framing details. 1. Incising assumed for Douglas Fir-Larch, Hem-Fir, and 2. Incising assumed for Douglas Fir-Larch, Hem-Fir, and Spruce- Spruce-Pine-Fir. Pine-Fir. 2. Design values based on Northern Species with no incising 3. Design values based on Northern Species with no incising assumed. assumed. 4. Shading indicates where triple trimmers are required. See text The trimmer hanger capacities listed in Table 7 are based for alternate 2-ply trimmer conditions. 5. Applies to 2x6 trimmer joist spans as well. on Southern Pine joist spans at 12" o.c. or 16" o.c. spacing (whichever controls). The reaction is a Table C7c. Trimmer Joist Hanger Vertical Capacity combination of the concentrated header load Pb/LJ and Based on Trimmer Span. the tributary uniform load between the trimmer and the Trimmer Span Minimum Capacity, lbs next adjacent joist. Another way of tabulating trimmer 8' 660 hanger capacities is shown in Table C7c based on 10' 860 trimmer spans. Table C7c is based on the header framing 12' 1060 into the trimmer at 1' (a=1', see Figure 35). Table C7c will be conservative for larger protrusions (larger â€œaâ€ 14' 1260 values.) Linear interpolation of tabulated values is 16' 1325 permitted. 18' 1430 Trimmer Joist Span Limited by Concentrated Load on Examples the Ledger 1) Assume a 2x10 Redwood joist spanning 12'-0" at Bolts or lag screws used to attach the trimmer hanger to 16" o.c. (per Table 2) framing around a 5' wide by 2'-6" the ledger are required to fully extend through the ledger deep chimney. Set a 6' header 3' from the end of the into the band joist or rim board. If a typical face trimmer joist. A triple trimmer joist is required since the mounted hanger is installed where only nails are used to span exceeds 8'-6". If the trimmer hanger does not attach attach the hanger to the ledger, the ledger would carry a through the ledger to the rim board or band joist, the large portion of the load. Since a concentrated load trimmer joist span is limited to 9'-8" per Table C7b. would be created on the ledger, it would be resisted by Several solutions exist: the bolts at the end of the ledger. As discussed under - Reduce all joist spans to 9'-8". LEDGER ATTACHMENT REQUIREMENTS, the - LJ/4 = 2'-5" so LJ + LJ/4 = 12'-1" total joist length, provisions for minimum distance, de, between the top of which would provide the same square footage. the ledger and the bottom row of fasteners (Figure 19) is - Place a post under the center of the header to reduce based on NDS 3.4.3.3(a) for shear design at connections. the header span. Based on this analysis, trimmer joist lengths would need to be limited to the maximum trimmer joist spans shown 2) Assume a 2x8 Western cedar joist spanning 8'-0" at in Table C7b, regardless of the trimmer joist species or 24" o.c. (per Table 2) framing around a 5' wide by 1.5' number of plies. Since this analysis is based on a simple deep bay window. Set a 6' header 2' from the end of the span trimmer joist, a trimmer joist with an overhang of trimmer joist. A double trimmer joist is permitted since up to LJ/4 would be conservative. The load on the end of the spacing is 24" o.c. If the trimmer hanger does not the cantilever would reduce the reaction at the ledger. attach through the ledger to the rim board or band joist, American Wood Council C14 Prescriptive Residential Wood Deck Construction Guide â€“ Commentary the trimmer joist span is limited to 5'-9" per Table C7b. 6" deep bay window. Set a 6' header 2' from the end of Several solutions exist: the trimmer joist. A double trimmer joist is permitted - Reduce all joist spans to 5'-9". since a = 24" which is less than amax = 25" in Table C7a. - Place a post under the center of the header to reduce However, if the trimmer hanger does not attach through the header span. the ledger to the rim board or band joist, the trimmer - Increase joist size to 2x10 which will span 8'-1" per joist span is limited to 11'-2" per Table C7b. Several Table C7b. solutions exist: - Reduce all joist spans to 11'-2". 3) Assume a 2x12 Southern Pine joist spanning 18'-0" - Place a post under the center of the header to reduce at 12" o.c. (per Table 2) framing around a 5' wide by 1'- the header span. REFERENCES ASTM F547-06 Standard Terminology of Nails for Use with Wood and Wood-Base Materials, ASTM, West 2015 International Building Code (IBC), International Conshohocken, PA, 2012. Code Council (ICC), Washington, DC, 2015. AWPA Book of Standards, American Wood Protection 2015 International Residential Code (IRC), International Association, Birmingham, AL, 2017. Code Council (ICC), Washington, DC, 2015. Carradine, D. M., Donald Bender, Joseph R. Loferski, AC174 Acceptance Criteria for Deck Board Span and Frank E. Woeste. â€œResidential Deck Ledger Ratings and Guardrail Systems (Guards and Handrails), Connection Testing and Design.â€ Wood Design Focus. International Code Council Evaluation Service, Vol. 16, No. 2. Forest Products Society. Madison, WI. Washington, DC, 2014. Summer 2006. ANSI/AWC NDS-2015 National Design Specification Loferski, Joseph R., Dustin Albright, and Frank E. (NDS) for Wood Construction, American Wood Council, Woeste. â€œTested Guardrail Post Connections for Leesburg, VA, 2015. Residential Decks.â€ Wood Design Focus. Vol. 16, No. 2. Forest Products Society. Madison, WI. Summer 2006. ASTM D245-06 Standard Practice for Establishing Structural Grades and Related Allowable Properties for Loferski, Joseph R. and Frank E. Woeste. â€œStrong Rail- Visually Graded Lumber, ASTM, West Conshohocken, Post Connections for Wooden Decks.â€ Journal of Light PA, 2011. Construction. Williston, VT. February 2005. ASTM D2555-06 Standard Practice for Establishing Policy for Evaluation of Recommended Spans for Span Clear Wood Strength Values, ASTM West Rated Decking Products, American Lumber Standard Conshohocken, PA, 2001. Committee, Germantown, MD. 2004. American Wood Council RESIDENTIAL MISCELLANEOUS APPLICATION Community and Economic Development City of Arlington â€¢ 18204 59th Ave NE â€¢ Arlington, WA 98223 â€¢ Phone (360) 403-3551 This application is required for Residential: Decks, Fences, Hot Tub/Spa, Pools, Retaining Walls and other similar in nature but not specified. See the ASSISTANCE BULLETINS for additional information and requirements. EACH BUILDING OR STRUCTURE REQUIRES A SEPARATE SUBMITTAL. SUBMIT ELECTRONIC FILES FOR EACH OF THE FOLLOWING; Incomplete applications will not be accepted. REQUIRED DOCUMENTS DECKS â€¢ Proof of approved Zoning Verification or Permit Number: _________________ â€¢ Residential Decks Assistance Bulletin: Complete page 4 â€¢ Site plan FENCES â€¢ Type of fencing: _______________________ â€¢ Site Plan HOT TUB/SPA â€¢ Manufacturerâ€™s Installation Documents â€¢ Site Plan ABOVE GROUND POOL â€¢ Manufacturerâ€™s Engineering and Installation Documents â€¢ Site Plan IN GROUND POOL â€¢ Manufacturerâ€™s Engineering and Installation Documents â€¢ Site Plan RETAINING WALL â€¢ Engineered plans â€¢ Site Plan OTHER â€¢ Describe: __________________________________________________________________________________ â€¢ Site Plan Type of Permit: Deck Fence Hot Tub/Spa Pool Retaining Wall _________________ Property Address: Project Valuation: Lot #: Parcel ID No.: Subdivision: Project Scope of Work: Primary Contact: Owner Contractor Owner Name: Home No.: Email Address: Cell No.: Mailing Address: City: State: Zip: Contractor Name: Office No.: Email Address: Cell No.: Mailing Address: City: State: Zip: L&I Contractor License Number: Expiration Date: I hereby certify that I am the Owner Contractor and authorized to sign this application and that the above information is correct and construction on, and the occupancy and the use of the above-described property will be in accordance with the laws, rules and regulation of the State of Washington, and the City of Arlington. Signature Print Name Date RESIDENTIAL DECKS #21 Please complete each item below (ft. = feet / in = inches A. Span of joists: 7 ft. in F. Size of joist: 2 in x 8 in On center spacing: 16" OC G. Ledger lag screw or bolt spacing: 11 in 9 6 B. Height of posts: ft. in Ledger lag screw or bolt diameter: in C. Span of support beam: 8 ft. in Ledger lag screw or bolt length: in D. Size of support beam: 4 in x 12 in H. Footing size: 18 in roundx in E. Size of post: 6 in x 6 in CAMOÂ® 5/16"x4" Structural Screws to be used for ledger, per manufacturer spacing REV2022 City of Arlington Pag e | 4 Permit #6146 - Arlington 9/25/24, 19:47 ï Back https://arlington.portal.iworq.net/ARLINGTON/permit/605/22897877 Page 1 of 3 Permit #6146 - Arlington 9/25/24, 19:47 Permit Information Permit Number: 6146 Permit Date: 09/04/2024 Project Name: New Deck Permit Issued: Permit Expires: Form Permit Type: RESIDENTIAL ZONING VERIFICAITON Status: ISSUED Property Information Parcel #: 01212900002400 8402 GILMAN WAY ARLINGTON, WA 98223 Plan Reviews 09/05/2024 - RESIDENTIAL ZONING VERIFICATION Approved - BUILDING Date: 09/12/2024 Completed Date: 09/10/2024 ------------------------ 09/05/2024 - RESIDENTIAL ZONING VERIFICATION Approved - PLANNING Date: 09/12/2024 Completed Date: 09/25/2024 ------------------------ 09/05/2024 - RESIDENTIAL ZONING VERIFICATION Approved - PW-ADMIN-GIS Date: 09/12/2024 Completed Date: 09/09/2024 - No comments, LT & JK ------------------------ 09/05/2024 - RESIDENTIAL ZONING VERIFICATION Approved - PW-SEW-REV Date: 09/12/2024 Completed Date: 09/09/2024 - No comments ------------------------ 09/05/2024 - RESIDENTIAL ZONING VERIFICATION Approved - PW-WAT-REV Date: 09/12/2024 Completed Date: 09/10/2024 - no comments for this review. Guas Letters 09/04/2024 - Web Form - Building Application Print https://arlington.portal.iworq.net/ARLINGTON/permit/605/22897877 Page 2 of 3 From: Jermaine Mize To: Kristin Foster Subject: Re: New Deck Building Permit Submittal Date: Friday, October 4, 2024 9:26:26 AM This message is from an External Sender This message came from outside the City of Arlington Good morning, Thank you for the update and I truly hope everything is okay with your colleague. Is there anything I can do now, to prep and ready in anticipation of next steps? Strong-DriveÂ® SDWSâ„¢ TIMBER Screw (Exterior Grade) strongtie.com Thanks again, have a great weekend. Jermaine Sent from my iPhone On Oct 4, 2024, at 09:09, Kristin Foster <kfoster@arlingtonwa.gov> wrote: ï»¿ Good morning, I have completed a preliminary review of the submittal for your new deck permit application and would like to review with the Building Official prior to providing you additional information. The Building Official has been unexpectedly out of the office this week and hopefully will be returning on Monday. I will go over the submittal with him when he returns and then reach out. Hope you have a great weekend.  <image001.png> Kristin Foster Permit Technician II Community and Economic Development 18204 59th Ave NE, Arlington, WA 98223 P. (360)403-3545 E. kfoster@arlingtonwa.gov CITY OF ARLINGTON 18204 59th Avenue NE, Arlington, WA 98223 INSPECTIONS: 360-403-3417 - Permit Center: 360-403-3551 BUILDING PERMIT 8402 GILMAN WAY Permit #: 6173 PERMIT EXPIRES 180 DAYS AFTER Parcel #: 01212900002400 DATE OF ISSUANCE. Scope of Work: Build and install 96 sq ft new composite deck. NO ROOF. Valuation: 9999.00 OWNER APPLICANT CONTRACTOR MIZE JERMAINE Jermaine Mize Wilder Custom Construction 8402 GILMAN WAY 8402 Gilman Way 13615 57th Ave NE ARLINGTON, WA 98223 Arlington, WA 98223 Marysville, WA 98271 7634581909 425-330-9303 LIC: 604 211 861 EXP: 01/31/2025 LIC: WILDECC824BT EXP: 05/13/2026 MECHANICAL CONTRACTOR PLUMBING CONTRACTOR LIC #: EXP: LIC #: EXP: JOB DESCRIPTION PERMIT TYPE: ACCESSORY STRUCTURE CODE YEAR: 2021 STORIES: 1 CONST. TYPE: VB DWELLING UNITS: OCC GROUP: R-3; Residential BUILDINGS: OCC LOAD: PERMIT APPROVAL The issuance or granting of this permit shall not be construed to be a permit for, or approval of, any violation of this Code or any other ordinance or order of the City, of any state or federal law, or of any order, proclamation, guidance advice or decision of the Governor of this State. To the extent the issuance or granting of this permit is interpreted to allow construction activity during any period of time when such construction is prohibited or restricted by any state or federal law, or order, proclamation, guidance advice or decision of the Governor of this State, this permit shall not authorize such work and shall not be valid. The building official is authorized to prevent occupancy or use of a structure where in violation of this Code, any other City ordinances of this jurisdiction or any other ordinance or executive order of the City, or of any state or federal law, or of any order, proclamation, guidance advice or decision of the Governor. The building official is authorized to suspend or revoke this permit if it is determined to be issued in error or on the basis of incorrect, inaccurate or incomplete information, or in violation of any City ordinance, regulation or order, state or federal law, or any order, proclamation, guidance or decision of the Governor. I AGREE TO COMPLY WITH CITY AND STATE LAWS REGULATING CONSTRUCTION AND IN DOING THE WORK AUTHORIZED THEREBY; NO PERSON WILL BE EMPLOYED IN VIOLATION OF THE LABOR CODE OF THE STATE OF WASHINGTON RELATING TO WORKMEN'S COMPENSATION INSURANCE AND RCW 18.27. THIS APPLICATION IS NOT A PERMIT UNTIL SIGNED BY THE BUILDING OFFICIAL OR HIS/HER DEPUTY AND ALL FEES ARE PAID. IT IS UNLAWFUL TO USE OR OCCUPY A BUILDING OR STRUCTURE UNTIL A FINAL INSPECTION HAS BEEN MADE AND APPROVAL OR A CERTIFICATE OF OCCUPANCY HAS BEEN GRANTED. IBC110/IRC110. SALES TAX NOTICE: Sales tax relating to construction and construction materials in the City of Arlington must be reported on your sales tax return form and coded City of Arlington #3101. 11/06/2024 Applicant Signature Date Building Official Date CONDITIONS Adhere to the construction and installation requirements as outlined in the 2018 American Wood Council Prescriptive Residential Wood Deck Construction Guide - attached. Approved job copy shall be onsite for inspections. Call for inspections. The property owner shall ensure that the construction project complies with all applicable zoning codes and regulations. The property owner shall also ensure that the construction project does not cause any adverse impact on the surrounding environment or community. The property owner shall be responsible for obtaining all necessary permits and approvals from the relevant authorities before commencing construction. The property owner shall ensure that the construction project complies with all applicable design review requirements. THIS PERMIT AUTHORIZES ONLY THE WORK NOTED. THIS PERMIT COVERS WORK TO BE DONE ON PRIVATE PROPERTY ONLY. ANY CONSTRUCTION ON THE PUBLIC DOMAIN (CURBS, SIDEWALKS, DRIVEWAYS, MARQUEES, ETC.) WILL REQUIRE SEPARATE PERMISSION. PERMIT FEES Date Description Fee Amount 11/07/2024 Building Plan Review $176.01 11/07/2024 Credit Card Service $5.28 11/07/2024 Processing/Technology $25.00 11/07/2024 Building Permit $270.77 11/07/2024 State Surcharge - 1st DU $6.50 Total Due: $483.56 Total Payment: $483.56 Balance Due: $0.00 CALL FOR INSPECTIONS Call by 3:30 pm for next day inspection, allow 48 hours for Fire Inspections When calling for an inspection please leave the following information: Permit Number, Type of Inspection being requested, and whether you prefer morning or afternoon INSPECTION INFORMATION Pass/Fail Permit #: 6173 Permit Date: 09/25/24 Permit Type: ACCESSORY STRUCTURE Project Name: Mize New Deck Applicant Name: Jermaine Mize Applicant Address: 8402 Gilman Way Applicant, City, State, Zip: Arlington, WA 98223 Contact: Jermaine Mize Phone: 7634581909 Email: jim82@mac.com Scope of Work: Build and install 96 sq ft new composite deck. NO ROOF. Valuation: 9999.00 Square Feet: 96 Number of Stories: 1 Construction Type: VB Occupancy Group: R-3; Residential ID Code: Permit Issued: 11/06/2024 Permit Expires: 10/29/2025 Form Permit Type: RESIDENTIAL ADDITION Status: COMPLETE Assigned To: Kristin Foster Property Parcel # Address Legal Description Owner Name Owner Phone Zoning 01212900002400 8402 GILMAN WAY AFN#202112095002 MIZE JERMAINE 107 UNIT LOT Contractors Contractor Primary Contact Phone Address Contractor Type License License # Wilder Custom 13615 57th Ave CONSTRUCTION 425-330-9303 COA 604 211 861 Construction NE CONTRACTOR Wilder Custom 13615 57th Ave CONSTRUCTION 425-330-9303 L&I WILDECC824BT Construction NE CONTRACTOR Inspections Date Inspection Type Description Scheduled Date Completed Date Inspector Status 04/28/2025 R20. ACCESSORY Can access balcony from 04/29/2025 04/29/2025 BUILDING Completed STRUCTURE rear of home, north side. - FINAL Approved Fees Fee Description Notes Amount Building Plan Review Table 4-2 $176.01 Credit Card Service $5.28 Processing/Technology $25.00 Building Permit Table 4-1 $270.77 State Surcharge - 1st DU Residential - 1st Unit $6.50 Credit Card Service $9.07 Total $492.63 Attached Letters Date Letter Description 11/06/2024 Building Permit 09/25/2024 Web Form - Building Application Payments Date Paid By Description Payment Type Accepted By Amount XBP Conf: 09/26/2024 $176.01 210950311 09/26/2024 210950311 Ameresia Lawlis $5.28 XBP Conf: 11/06/2024 $302.27 214340613 11/06/2024 214340613 Ameresia Lawlis $9.07 Outstanding Balance $0.00 Notes Date Note Created By: 04/02/2025 sent expiration notice Hannah Hardwick 2018 American Wood Council Prescriptive Residential Wood Deck Construction Guide was 11/06/2024 Kristin Foster provided to the applicant for the construction of the deck. â€œHopefully this is exactly what youâ€™re looking for. Simpson Z. Max, Joist, Ledger, Beams: standard post to bean connects. Ledger fasten pro ledger locker half in by 5in ledger locker 11/05/2024 Post Ledger lag screw or bolt spacing: Kristin Foster 24th oc Ledger lag screw or bolt diameter: Ledger fasten pro ledger locker half in by 5in ledger locker Ledger lag screw or bolt length: 3/8 by 5inâ€ Uploaded Files Date File Name 11/06/2024 23103956-20241106_BLD6173_IssuedPermit.pdf 09/26/2024 22548688-20240925_BLD6173_Application.pdf 09/26/2024 22548689-20240925_BLD6173_DeckHandout.pdf 09/26/2024 22548690-20240925_BLD6173_LotonPlatMap.png 09/26/2024 22548685-20240925_BLD6173_PlatMap.jpg 09/26/2024 22548686-20240925_BLD6173_SitePlan.png 09/26/2024 22548687-20240925_BLD6173_ZoningVerificationApproval.pdf