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DECK GUIDELINES Page 1 Rev 02/11 CITY OF MADISON HEIGHTS COMMUNITY DEVELOPMENT DEPARTMENT BUILDING DIVISION (248) 583-0831 DECK GUIDELINES The following standards are to be followed when constructing a deck or raised patio: 1 All support posts/columns on attached decks shall be set on concrete 42" below grade. Unattached decks must extend below any organic soils to bearing soil. Footings for concrete patios that may be built upon are required to be 8” x 42" with a 4" slab. If there is no intent to build on the patio slab now, or in the future, a 4” x 24” ratwall is recommended. 2. All walking surfaces 30” or more above finished grade require guardrails. All guardrails installed must be a minimum of 36" in height from the top of the deck to the top of the handrail. Guards must be designed so that a 4” ball can not pass though the guard at any point and may not have any ladderable elements.. 3. All material in contact with the ground or masonry shall be .6 pressure treated and material used for the remaining structure of the deck shall be pressure treated or rot resistant species. 4. Deck heights shall be no higher than 4" below any threshold or entrance leading into the home. 6. Provide weed control under deck. Two sets of construction drawings of the deck will be required along with the Building Permit application. Attached worksheets may also be returned with the plan. Page 2 Page 3 RAILING POST-TO-DECK FRAMING . " The railing connection is one of the more crucial connections pertaining to safety, and it is often inadequately constructed. In order to provide the required load resistance at the hand rail, the post must not only be fastened to the rim joist, but also tied back into the joist framing. Machine bolts tl-lroUgh the post and rim joist alone do not typically meet the performance requirements of the code. The details shown below have been shown through testing to resist tile forces called out by the codes. SIMPSON SOLUTION 16" MAX. o HD2AHDG Holdown: Horizontal Application o .~ For more information on this application, see technical bulletin T-HD2AGRDRL06 Code Requirements When required v Guards shall be located along open-sided walking surfaces, porches, balconies or raised floor surfaces more than 30" above the floor or grade below. - IRG 2006, Section R312.1 / IBG 2006, Section 1013.1 Height v' Guards shall be a minimum of 36" tall (IRC) or 42" tall (IBC) - IRG 2006, Section R312.1 / IBG 2006, Section 1013.2 Load Resistance v Handrail assemblies and guards shall be able to resist a single concentrated load of 200 pounds, applied in any direction at any point along the top (IRC & IBC), and have attachment devices and supporting structure to transfer this loading to appropriate structural elements of the building (IBC only). - IRG 2006, Table R301.5/ IBG 2006, Section 160111 Selection of products based upon performance and/or suitability for a specific application should be made by a qualified professiqnal. Simpson recommends that '.product choice be approved by the local building department before construction begins. rlrI'[Q;@ HOTDIPD ww GALVANIZED" G1BS ~Jf1!J(!J SlJI/I/ILESSSlFEL· These products are available with aZMAX® or hot-dipped galvanized finish. Stainless steel connectors are also available for higher exposure environments or applications using certain preservative treated woods. See page 5 for more details. F-DECKCODE07 ©2007 SIMPSON STRONG-TIE COMPANY INC. DECK FRAMING COI~NECTION GUIDE I 13 Page 4 1. The allowable loads have been Increased 60% for wind or earthquake loading with no further increase allowed. 2. Load values are valid if the product is flush with the end of the framing member or installed away from the end. 3. The guardrail post illustration above addresses an outward force on the guardrail. An additional DTT2 can be 0112 Deck Post Connectors The DTT2 is a safe, cos.t-effective way to attaGI\ deck-railing posts to the deck framing. Because the post is tied back into the deck joists, rather than to the rim joist alone, the connection is stronger than typical through-bolt installations and complies with IRC and IBC code requirements regarding handrail and guardrail post connections for decks. The DTT2 also complies with the new IRC requirements for laterally tying the deck to the house. Additionally, the versatile DTT2 is load rated as a holdown for light-duty shearwalls and braced wall panel applications. The DTT2 fastens easily to a single 2x joist or stud using Simpson Strong-Tie® Strong-Drive® SDS screws (included) and accepts a W machine bolt or anchor bolt The new DTT2SS is made from stainless steel for applications in higher exposure environments. Whether it's a deck guardrail post application or the lateral-load connection from the deck to the adjacent structure, the new stainless-steel DTT2 is the best choice for seaside applications or those calling for more corrosive preservative-treated lumber formulations. It fastens to the framing members with stainless-steel Simpson Strong-Tie Strong-Drive SDS wood screws (included). The new DTT2Z-SDS2.5 is our standard DTT2Z packaged with 2W Simpson Strong-Tie Strong-Drive SDS wood screws instead of the standard 1y," fasteners. These longer screws allow the DTT2Z to achieve a load capacity in excess of 2100 Ibs. when used as a holdown on double studs in a shearwall application. The DTT2Z-SDS2.5 is also suitable in deck applications when double 2x members are used for deck joists or blocking. MATERIAL: DTT2ZIDTT2SS-14 gauge FINISH: DTT2Z-ZMAX® coating; DTT2SS-Stainless steel; see Corrosion Information, page 18-19. INSTALLATION: Use all specified fasteners. See General Notes. • A standard cut washer (refer to General Notes) must be installed between the nut and the seat • Simpson Strong-Tie SDS screws install best with a low speed high torque drill with a %" hex head driver. CODES: See page 20 for Code Reference Key Chart. • These products are available with additional corrosion protection. Additional products on • this page may also be available with this option, check with Simpson Strong-Tie for details. • I Model No. ff Anchor Diameter Fasteners Minimum Wood Member Thickness Allowable Tension Load Code Ret. DF/SP SPF/HF (100) (160)' (100l (160)' OTT2 '0/" y, 8-S0S v."x1 \1," 1'h 1825 1825 1440 1800 16, L8,F5 3 2000 2145 1440 1835 DTT2Z-S0S2.5 '0/" 'h 8-S0S '/.,"x2'h" 3 2145 2145 2105 2105 170 added at the lower bolt to address an inward force. oP1Z Deck Post Tie The DPTZ Deck Post Tie products are used to attach 2x4 (DPT5Z) or 4x4 (DPT7Z) vertical posts to the side of stringers, rims or other wood members. MATERIAL: 14 gauge FINISH: ZMAX coating; see Corrosion Information, page 18-19. INSTALLATION: • Use specified HDG fasteners. See General Notes. • Install in pairs. • Install with two %" through bolts into side member and 5-1 Odx1 Y2 to post for DPT5Z or 5-10d for DPT7Z. ,. These products are approved for installation with the Strong-Drive SO Structural-Connector screw. See page 30 for the correct substitution and SO screw size. Typical DPT7Z Stairway Installation (DPT5Z similar) DTT2 installed as a lateral connector for a deck guardrail post. For more information on guardrail post connections, see technical bulletin T-GRDRLPST. iL__ ... ._.~._._._.~_ ... _.,_,__.. _._~_, __. .... Typical Deck-to-House Lateral Load Connection II 183 Page 5 Prescriptive Residential Wood Deck Construction Guide Based on the 2009 Intel'national Residential Code guard post attachment footing .J 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 © 2010 American Forest & Paper Association, Inc. Page 6 2 PRESCRIPTIVE RESIDENTIAL WOOD DECK CONSTRUCTION GUIDE CONTENTS MINIMUM REQUIREMENTS DECKTI\TG REQUIREMENTS JOIST SIZE BEAM SIZE & ASSEMBLY REQUIR~MENTS DECK FRAMING PLAN JOIST-TO-BEAM CONNECTION JOIST HANGERS POST REQUIREMENTS RIM JOIST REQUIREMENTS FOOTINGS LEDGER ATTACHMENT REQUIREMENTS 2 PROHIBITED LEDGER ATTACHMENTS 12 3 LEDGER BOARD FASTENERS 12 3 FREE-STANDING DECKS 14 5 DECK STABILITy 14 6 GUARD REQUIREMENTS 15 7 GUARD POST ATTACHMENTS 16 7 STAIR REQUIREMENTS , 17 7 STAIR HANDRAIL REQUIREMENTS 18 8 STAIR FOOTING REQUIREMENTS 19 9 STAIR LIGHTING REQUIREMENTS 19 10 FRAMING AT CHIMNEY OR BAY WINDOW 19 MINIMUM REQUIREMENTS 1. This document applies to single level residential wood decks only. 2. All lumber shall be identified by the grade mark of, or certificate of inspection issued by, an approved lumber grading or inspection bureau or agency (www.alsc.org). All lumber shall be a naturally durable species (such as Redwood or Western Cedars) or be pressure-treated with an approved process and preservative in accordance with American Wood Protection Association standards (such as but not limited to those shown in Table 1) [R317 and R318]. All lumber in contact with the ground shall be approved preservative treated wood suitable for ground contact. [R317.1.2] 3. All nails shall meet the requirements ofASTM F 1667. Threaded nails as stated in this document include helical (spiral) and annular (ring-shank) nails. Wood screws shall meet the requirements of ANSIIASME BI8.6.1. Bolts and lag screws shall meet the requirements ofANSIIASME BI8.2.1 .. 4. Throughout this document, 12" diameter bolts and lag screws are specified for various connections. Edge distance and spacing requirements are based on 12" diameter fasteners. If larger (or smaller) fasteners are specified, edge distance and spacing needs to be adjusted. 5. To resist corrosion, the following is required [R317.3]: • All screws, bolts, and nails for use with preservative treated wood shall be hot-dipped zinc-coated galvanized steel, stainless steel, silicon bronze, or copper. Fasteners to be hot-dipped galvanized shall meet the requirements ofASTMA 153, Standard Specification for Zinc Coating (Hot-Dip) on Iron and Steel Hardware, Class D for fasteners 3/8" diameter and smaller or Class C for fasteners with diameters over 3/8". • Fasteners other than nails and timber rivets shall be permitted to be of mechanically deposited zinc coated steel with coating weights in accordance with ASTM B 695, Class 55, minimum. • All hardware Goist hangers, cast-in-place post anchors, etc.) shall be galvanized or shall be stainless steel. Hardware to be hot-dipped prior to fabrication shall meet ASTMA 653, Standard Specificationfor Steel Sheet, Zinc-Coated (Galvanized) or Zinc-Iron Alloy-Coated (Galvannealed) by the Hot-Dip Process, G-185 coating. Hardware to be hot-dipped galvanized after fabrication shall meet ASTMA123, Specification for Zinc (Hot-Dip Galvanized) Coatings on Iron and Steel Products. • Fasteners and connectors exposed to salt water or located within 300 feet of a salt water shoreline shall be stainless steel grade 304 or 316. • Other coated or non-ferrous fasteners or hardware shall be as approved by the authority having jurisdiction. 6. Decks supporting large concentrated loads such as hot tubs are beyond the scope of this document. 7. This document does not apply to decks which will experience snow loads, snow drift loads, or sliding snow loads that exceed 40 psf. This document does not address wind or seismic design issues. 8. Flashing shall be corrosion-resistant metal [R703.8] of minimum nominal 0.OI9-inch thickness or approved non-metallic material. Aluminum should not be used in direct contact with lumber treated with preservatives that contain copper such as ACQ, Copper Azole, or ACZA. 9. Decks shall not be used or occupied until final inspection and approval is obtained. 10. This document is not intended to preclude the use of other construction methods or materials not shown herein. American Wood Council Page 7 3 PRESCRIPTIVE RESIDENTIAL WOOD DECK CONSTRUCTION GUIDE Table 1. Common preservative treatments and retention levels (pcf) f i b ' urn er In ground contac.t a or sawn Species ACQ-B ACQ-C ACQ-D CA-B CuN-W Southern Pine DAD DAD DAD 0.21 0.11 Douglas Fir-Larch DAD DAD NR 0.21 0.11 Hem-Fir DAD DAD DAD 0.21 0.11 Ponderosa Pine DAD DAD DAD 0.21 0.11 Red Pine DAD DAD DAD 0.21 0.11 Spruce-Pine-Fir NR DAD NR NR NR Redwood NR NR NR NR NR • Preservatives and retentions listed In Table 1 are based on the Amencan Wood Protectton Association (AWPA) Book of Standards. NR =Treatments Not Recommended. DECKING REQUIREMENTS All decking material shall be composed of dimension lumber (2" nominal thickness) or span rated decking in accordance with the American Lumber Standard Committee Policyfor Evaluation ofRecommended Spansfor Span Rated Decking Products (November 5, 2004). Attach decking to each joist with 2-8d threaded nails or 2-#8 screws. Space decking boards approximately 1/8" apart. See Figure 11 for decking connection requirements at the rim joist. Decking may be placed from an angle perpendicular to the joists to an angle of45 degrees to the joists. Each segment of decking must bear on a minimum of4 joists (or 4 supports). Table 2. Maximum Joist Spans (LJ) Decking not meeting these requirements may be substituted when the product has been approved by the authority having jurisdiction. JOIST SIZE The span of a joist is measured from the centerline of bearing at one end ofthe joist to the centerline of bearing at the other end of the joist and does not include the length ofthe overhangs. Use Table 2 to determine joist span based on lumber size andjoist spacing. See Figure 1 and Figure 2 for joist span types. Species Southern Pine Douglas Fir- Larch, Hem-Fir, SPF3 Redwood, Western Cedars 4 Ponderosa Pine, Red Pine 4 Joist Spacing (o.c.) Without Overhangs1 With Overhangs up to LJ/42 Size 12" 16" 24" 12" 16" 24" 2x8 13' - 8" 12' - 5" 10' - 2" 10' - 9" 10' - 9" 10' - 2" 2x10 17' - 5" 15' - 10" 13' - 1" 15' - 6" 15' - 6" 13' - 1" 2x12 18' - 0" 18' - 0" 15' - 5" 18' - 0" 18' - 0" 15' - 5" 2x8 12' - 6" 11' - 1" 9' - 1" 9' - 5" 9' - 5" 9' - 1" 2x10 15' - 8" 13'-7" 11' - 1" 13' - 7" 13'-7" 11' - 1" 2x12 18' - 0" 15' - 9" 12' - 10" 18' - 0" 15' - 9" 12' -10" 2x8 11' - 8" 10' - 7" 8' - 8" 8' - 6" 8' - 6" 8' - 6" 2x10 14'-11" 13' - 0" 10' - 7" 12' - 3" 12' - 3" 10' -7" 2x12 17' - 5" 15' - 1" 12' - 4" 16' - 5" 15' - 1" 12' - 4" .. 1. Assumes 40 psf live load, 10 psf dead load, U360 deflection, No.2 grade, and wet service conditions. See Figure 1B. 2. Assumes 40 psf live load, 10 psf dead load, Ll180 cantilever deflection with 220 Ib point load, No.2 grade, and wet service conditions. See Figure 1A and Figure 2. 3. Incising assumed for refractory species including Douglas fir-larch, hem-fir, and spruce-pine-fir. 4. Design values based on northern species with no incising assumed. American Forest 8< Paper Association Page 8 ------- 4 PRESCRIPTIVE RESIDENTIAL WOOD DECK CONSTRUCTION GUIDE Figure 1A. Joist Span - Deck Attached at House and Bearing Over Beam existing wall ..... r optional overhang ij~_J_C_= ~r~' -~.=~JI'~C t=_=l c:==tr:==J..C::==r==JC=:lf==:JC=:J.c:::x:==1C.=.][t=h=:JI==:JjC:::::J.C~l -JmC ~ __ _ _ JOIS . anger~·~....... beam (flush.-.-~_ I ledger board joist --post tight bearing) LJ/4 maximum Joist Span (LJ): see Table 2 _.,., ,'", _ , 'w _ .. ' _ " , ,." ,~_ ,_ _ .. " .._".."" " _ " ' ' ' ..' ' mm ' ~~_"_._.._m'" . overhang Figure 1B. Joist Span - Joists Attached at House and to Side of Beam /~ joist existing wall .... beam*--.. X~.1--joist han~er joist hanger '-.- .......f' '! post-....... *Note: beam depth must be equal to or greater than joist depth if joist hangers are used ledgerboard -1-1 Figure 2. Joist Span - Free Standing Deck r optional overhang optional overl'iang ~ M~J[==~[:·=~===========[:·::~t==J[=~-.•.•. •. - nm jOist nm JOIst ---~~-- beam- (flush, tight _ bearing) --post - joist beam· (flush, tight bearing) ----, ~ , LJ/4 maximum overhang Joist Span (LJ):see Table 2 i LJ/4 maximum i overhang I American Wood Council Page 9 5 PRESCRIPTIVE RESIDENTIAL WOOD DECK CONSTRUCTION GUIDE BEAM SIZE & ASSEMBLY REQUIREMENTS Joists shall not frame in from opposite sides ofthe 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 centerline up to LB/4 as shown in Figure 3. Joists may bear on the beam and Where multiple 2x members are used, the deck's beam is extend past the beam centerline up to L/4 as shown in assembled by attaching the members identified in Table Figures IA and 2, or the joists may attach to the side of 3 in accordance with Figure 4. [Table R602.3(1)] the beam with joist hangers as shown in Figure IB. Table 3. Deck Beam Spans (LB)1 for Joists Framing from One Side Only Joist Spans (LJ) Less Than or Equal to: Species Size4 6' 8' 10' 12' 14' 16' 18' 2-2x6 l' - 1" 6' - 2" 5' - 6" 5' - 0" 4' - 8" 4' - 4" 4' - 1" 2-2x8 9' - 2" l' - 11" l' - 1" 6' - 6" 6' - 0" 5' - 7" 5' - 3" 2-2x10 11' - 10" 10' - 3" 9' - 2" 8' - 5" l' - 9" l' - 3" 6' - 10" Southern 2-2x12 13'-11" 12'-0" 10'-9" 9'-10" 9'-1" 8'-6" 8'-0" Pine 3-2x6 8' - 7" l' - 8" 6' - 11" 6' - 3" 5' - 10" 5' - 5" 5' - 2" 3-2x8 11' - 4" 9' - 11" 8' - 11" 8' - 1" l' - 6" l' - 0" 6' - 7" 3-2x10 14'-5" 12'-10" 11'-6" 10'-6" 9'-9" 9'-1" 8'-7" 3-2x12 11'-5" 15'-1" 13'-6" 12'-4" 11'-5" 10'-8" 10'-1" 3x6 or 2-2x6 5' - 5" 4' - 8" 4' - 2" 3' - 10" 3' - 6" 3' - 1" 2' - 9" Douglas Fir 3x8or2-2x8 3x10or2-2x10 6'-10" 8'-4" 5'-11" 1'-3" 5'-4" 6'-6" 4'-10" 5'-11" 4'-6" 5'-6" 4'-1" 5'-1" 3'-8" 4'-8" Larch2 , 3x12or2-2x12 9'-8" 8'-5" 1'-6" 6'-10" 6'-4" 5'-11" 5'-7" Hem-Fir, SPF2 , Redwood, Western 4x6 4x8 4x10 6'-5" 8' - 5" 9' - 11" 5'-6" l' - 3" 8' - 7" 4'-11" 6' - 6" l' - 8" 4'-6" 5' - 11" l' - 0" 4'-2" 5' - 6" 6' - 6" 3'-11" 5' - 2" 6' - 1" 3'-8" 4' - 10" 5' - 8" Cedars, 4x12 11' - 5" 9' - 11" 8' - 10" 8' - 1n l' - 6" l' - 0" 6' - 7" Ponderosa Pine3 , Red Pine3 3-2x6 3-2x8 1'-4" 9' - 8" 6'-8" 8' - 6" 6'-0" l' - 7" 5'-6" 6' - 11" 5'-1" 6' - 5" 4'-9" 6' - 0" 4'-6" 5' - 8" 3-2x10 12'-0" 10'-5" 9'-4" 8'-6" 1'-10" 1'-4" 6'-11" 3-2x12 13' - 11" 12' - 1" 10' - 9" 9' - 10" 9' - 1" 8' - 6" 8' - 1" 1. Assumes 40 psf live load, 10 psf dead load, U360 simple span beam deflection limit, U180 cantilever deflection limit, No.2 grade, and wet service conditions. 2. Incising assumed for refractory species including 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). Figure 3: Beam Span Types joists above "'""'7\ optional overhang (may ~:::::~~~~:~~~~~~~/~/~\,_w~~~~~~~~~_o_c~ewu_t_B_t_e_a~~~fi_e_n_d~J~:] L __.•..__ .•..._~. _,__",,__, '.__'~'.'._._.~~._~_~.-,._. ,_j I \ ' I beam '-beamsp/lcesat interior post locations -post, typical =1 ""--La-/4-m-a-xL..l. beam span (La): see TableS beamspt:lll (La): sealable 3 ~al4~ax., overhang overhang , American Forest & Paper Association Page 10 • • • • • 6 \__·-t+_·-~--++~ "---"--------'---"---'-""--'--------"~----------'---- .. ---- --t----·------· .'-' round or square footmg: see Table 4..".""..""""." I I" "'l i-'-~~.Ll--+--\-'-'-~--i.LLL~--L.L~_--W~~--'-UW-.~--'+--+----'U--'---'-1 PRESCRIPTIVE RESIDENTIAL WOOD DECK CONSTRUCTION GUIDE Figure 4. Beam Assembly Details 10d threaded nail or #10 wood 2 threaded nails or screws at each end or screw ~3n long, staggered in splice end; splices shall be located only over interior posts (Figure 3) " ..,, •........_~._ ~._~-~~.~._._ ~._,~.~--~~»,_ ~-----.~----~~~""~ .. =~ . ....,,-,_ ..,\~ -_.~--~-~~'.~~--_.- "'W~"'~'_W"W~'~~_w~_,~, "W",w_,"~_,_~~" •. _ •..w..w~~,.~_, ..i\::''''~.~-.'_''-'W'wW" ""WW"•. ) • If a beam is constructed with 3-members, 16" attach each outside member to the inside typical member as shown here. DECK FRAMING PLAN A framing plan shows the joist and beam layout; the location of the ledger board, posts, and footings, and the type, size, and spacing of the ledger board fasteners. See Figure 5 for an example of a typical deck framing plan. Figure 5. Typical Deck Framing Plan _x_ledger ~T board with ;;z" dia. bolts/Jag screws/anchors @_"oncenter ~I I- = (see Table 5) (I) I ~II ..J ),- joist hanger: __. _ lbs - j II (see Table 3A) ~ ! Q.!,....I °1 trimmer hanger: __ !bs 1a1 (see Table 1) '~, rim joist xl rn EI ai ~I~ stair stringers: -J t i5 I cut Of solid span:_'-_" I (see Figure 28) ! LaM max. ( "dia. or " x ") x " thick - " deep lB/4 max. 1 r--' ......... .=""."".==,== .....j...... ',,- ..... overhang beam span(la): see Table:3 overhang treads:_x_ single, double, or triple _... x _: La:: _' - _.. " (see Table 6) American Wood Council Page 11 7 PRESCRIPTIVE RESIDENTIAL WOOD DECK CONSTRUCTION GUIDE JOIST-TO-BEAM CONNECTION Each joist shall be attached to the beam as shown in Figure 6. Joists may bear on and overhang past the beam a maximum of LJ/4. Use Option I or Option 2 to attach the joist to the beam. Option I shall only be used if the deck is attached to the house with a ledger (see LEDGER ATTACHMENT REQUIREMENTS) or as shown in Figure 23. Mechanical fasteners or hurricane clips used as shown in Option 2 must have a minimum capacity of 100 Ibs in both uplift and lateral load directions. Joists may also attach to the side ofthe beam with joist hangers per Option 3. Joists shall not frame in from opposite sides of the same beam. See JOIST HANGERS for more information. Hangers, clips, and mechanical fasteners shall be galvanized or stainless steel (see MINIMUM REQUIREMENTS). Figure 6: Joist-to-Beam Detail OPTION 3** top of beam and joist must be atSame elevation JOIST HANGERS Figure 7: Typical Joist Hangers Joist hangers, as shown in Figure 7, shall each have a Joist hanger with inside flanges minimum download capacity in accordance with Table 3A. The joist hanger shall be selected from an approved manufacturer's product data based on the dimensions of the joist or header it is carrying. Joist hangers shall be galvanized or stainless steel (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 Download Capacity " " ., " " " " " " " " " Joist Size Minimum Capacity, Ibs 2x8 600 2x10 700 2x12 800 POST REQUIREMENTS notching the 6x6 as shown in Figure 8 or by providing All deck post sizes shall be 6x6 (nominal) or larger, and an approved post cap to connect the beam and post as the maximum height shall be 14'-0" measured to the shown in Figure 10. All 3-ply beams shall be connected underside of the beam. Posts shall be centered on to the post by a post cap. All thru-bolts shall have footings. Cut ends of posts shall be field treated with an washers under the bolt head and nut. Attachment of the approved preservative (such as copper naphthenate) beam to the side of the post without notching is [R402.l.2]. The beam shall be attached to the post by prohibited (see Figure 9). American Forest &. Paper Association Page 12 8 ~ - minimum wood screws PRESCRIPTIVE RESIDENTIAL WOOD DECK CONSTRUCTION GUIDE Figure 8. Post-to-Beam Attachment Figure 9. Prohibited Post-to-Beam Attachment Requirements Condition (1) 3)( or 4)( or (2) 2)( beam ~ F-l~#~j::l), ,.. >." (2)1;2" diameter thru· ~/ bolts with washers .. 1"'"'' beam must bear fUlly on 6)(6 notch --+--''''-I::'' 6x6 min. ~ notch post to accomodale beam RIM JOIST REQUIREMENTS Figure 10. Alternate Approved Post-to-Beam Attach a continuous rimjoist to the ends ofjoists as Post Cap Attachment 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 jOistsT~~~ / ;;securectecking to top of rim joist with / " / 100 threaded nails or#10 x 3" ~ r ~ minimum wood screws@6"0.c. ~ attach rim joist to end of each Joist with (3) 10d threaded nails or (3) #10 x 3" American Wood Council Page 13 9 PRESCRIPTIVE RESIDENTIAL WOOD DECK CONSTRUCTION GUIDE FOOTINGS [R403] See Figure 12 and Table 4 for footing size, footing thickness, and post attachment options and requirements. All footings shall bear on solid ground and shall be placed at least 12 inches below the undisturbed ground Sllrf~lce or below the fi'ost line, whichever is deeper. Contact the authority having jurisdiction to determine the specified frost line. Bearing conditions shall be verified in the field by the building official prior to placement of concrete. Where the building official determines that in-place soils with an allowable bearing capacity of less than 1,500 psf are likely to be present at the site, the allowable bearing capacity shall be determined by a soils investigation. DECK FOOTINGS CLOSER THAN 5'-0" TO AN EXISTING EXTERIOR HOUSE WALL MUST BEAR AT THE SAME ELEVATION AS THE FOOTING OF THE EXISTING HOUSE FOUNDATION. Do not construct footings over utility lines or enclosed meters. Contact local utilities (call 811) before digging. Pre-manufactured post anchors shall be galvanized. See MINIMUM REQUIREMENTS. Table 4 F 00fmg S·Izes Beam Span, LB Joist Span LJ Round Footing Diameter Square Footing Dimension Footing Thickness2 <10' 15" 13" 6" 6' <14' 17" 15" 6" <18' 20" 18" 7" <10' 17" 15" 6" 8' <14' 20" 18" 8" <18' 23" 21" 9" <10' 19" 17" 7" 10' <14' 22" 20" 9" <18' 25" 23" 10" <10' 21" 19" 8" 12' <14' 24" 22" 10" <18' 28" 26" 11" <10' 22" 20" 9" 14' <14' 26" 24" 11" <18' 30" 28" 12" <10' 24" 22" 9" 16' <14' 28" 26" 12" <18' 32" 30" 13" <10' 25" 23" 10" 18' <14' 30" 28" 12" <18' 34" 32" 14" 1. Assumes 1,500 psf sOil beanng capacity. 2. Assumes 2,500 psi compressive strength of concrete. Coordinate footing thickness with post base and anchor requirements. Figure 12. Typical Footing Options {\ '\ Cut ends ofposts shall be I\f posts must be i l \f-T field treated with an approved! centered on footing Jl: preservative (such as copper I grade .. 1 _ naphthenate) 4. Ifootings must bear ! on solid ground American Forest &. Paper Association Page 14 LEDGER ATTACHMENT REQUIREMENTS [R502.2.2J GENERAL: Attach the ledger board, which shall be equal to or greater than the deck joist depth but less than or equal to the rimjoist depth, to the existing exterior wall in accordance with Figure 14 through Figure 16. When attachments are made to the existing house band joist, the band joist shall be capable of supporting the new deck. If this cannot be verified or conditions at the existing house differ from the details herein, then either a free-standing deck or full plan submission is required. See FREE-STANDING DECKS. SIDING AND FLASHING: House siding or the exterior finish system must be removed prior to installation of the ledger board. Approved corrosion resistant flashing is required at any ledger board connection to a wall of wood framed construction (see MINIMUM REQUIREMENTS). See Figure 14 for continuous flashing with drip edge. The threshold shall be carefully flashed and caulked to prevent water intrusion due to splash from the deck or melting snow and ice. MANUFACTURED WOOD I-JOIST: The term "1 Joist" denotes manufactured wood "I" joists (see Figure 13A). Many new homes constructed with wood I-joists Figure 13A. Wood I-Joist Profile include 1" or thicker engineered wood products (EWP) such as oriented strand board (OSB) or structural composite lumber (SCL) including laminated veneer lumber (LVL) - as band joists (or rim boards) that can support the attachment of a deck (see Figure 14). However, some older homes might be constructed with band boards that are too thin (less than 1") to support a deck. In such cases, a free-standing deck or a full plan submission is required. MANUFACTURED WOOD TRUSS: A metal plate connected wood truss (MPCWT) is an engineered, prefabricated structural component designed for each specific application. MPCWT's used in residential floors are often installed with a 2x4 lumber "ribbon" at the ends of the trusses (see Figure 13B) to tie the ends ofthe trusses together. The ribbon board, by itself, is not intended to support the deck ledger and deck. Installing residential decks when the floor system for the house uses MPCWT requires a standard detail provided by the truss designer, a free-standing deck, or a full plan submission. Refer to the WTCA Technical Note Attachment ofResidential Decks to Wood Truss Floor Systems for special blocking details and attachment requirements (www.sbcindustry.com). Figure 13B. Metal Plate Connected (MPC) Wood Floor Trusses with a 2x4 Lumber "Ribbon" at the Ends of the Trusses 2x4 RIBBON BOARD - not intended for ( __mem American Wood Council Page 15 11 -,-1------11-- deck joist J ----r-·1J2" diameter approved embed anchors 14;;;;;:~~:-~ r------- PRESCRIPTIVE RESIDENTIAL WOOD DECK CONSTRUCTION GUIDE Figure 14. General Attachment of Ledger Board to Band Joist or Rim Board remove siding atledger prior to installation threshold carefully flashed and caulked to prevent water intrusion .".----- continuous flashing 2x ledger board; must be greater -+-1-----"'-4- 1/2"diameter lag .. exterior sheathing existing stud wall--_.......I 1-5/8" min, 5" max. 2"min ------,.."".:-L-~ .--J.~:::::~H'---I:.I-------; • ". Figure 15. Attachment of Ledger Board to Foundation Wall (Concrete or Solid Masonry) deck joist existing concrete _ ,< or solid masonry • wall fo approved expansion, epoxy, or adhesive anchors wifhWasoors 2x ledger board; must be greater .. .. 3J.._----"'''-"t-1/2'' diameter joist hanger than or equal to the size of the jelist Figure 16. Attachment of Ledger Board to Foundation Wall (Hollow Masonry) existing 2x band joist or 1" minimum EWP rim board 2x floor joist. wood I-joist. f or MPCWT existing foundation wall extending pastjaist hanger deck joist screws or through-bolts with washers than or equal to the depth of the deck Joist and no greater than the depth oHbe band joist per manufacturer recommendations existing hollow ----p"=4== masonry wall block cells filled- with grout or concrete at anchor locations (new construction) I" to resist corrosion and decay, this area. should be caulked epOxy or adhesive anchQrswith Washers \ • joist hanger -I 2x ledger board; must be greater 8" block wall than or equal to the size of the joist minimum American Forest &. Paper Association Page 16 12 PRESCRIPTIVE RESIDENTIAL WOOD DECK CONSTRUCTION GUIDE PROHIBITED LEDGER ATTACHMENTS Attachments to exterior veneers (brick, masonry, stone) and to cantilevered floor overhangs or bay windows are prohibited (see Figures 17 and 18). In such cases the deck shall be free-standing (see FREE-STANDING DECKS). Figure 17. No Attachment to or Through Figure 18. No Attachment to House Overhang Exterior Veneers (Brick, Masonry, Stone) LEDGER BOARD FASTENERS nominal lumber band joist (I-W' actual) or EWP rim Only those fasteners noted below are permitted. LEAD board bearing on a sill plate or wall plate shall be ANCHORS ARE PROHIBITED. constructed with Yz" lag screws or bolts with washers per Table 5 and Figure 19 (see MINIMUM Deck ledger connection to band joist or rim board. REQUIREMENTS). The connection between a deck ledger and a 2-inch Table 5. Fastener Spacing for a Southern Pine, Douglas Fir-Larch, or Hem-Fir Deck Ledger and a 2-inch Nominal Solid-Sawn Spruce-Pine-Fir7 • 9 Band Joist or EWP Rim Board6 36 (Deck Live Load = 40 psf, Deck Dead Load = 10 pst)' , Rim Board 6'-0" 6'-1" 8'-1" 10'-1" 12'-1" 14'-1" 16'·1" Joist Span 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 Fasteners4 ,:J %" diameter lag screw with '5/3z" maximum sheathing1 1"EWPt5 1-'/8" EWP 6 1-%" Lumber7 ,9 24" 28" 30" 18" 21" 23" 14" 16" 18" 12" 14" 15" 10" 12" 13" 9" 10" 11" 8" 9" 10" W' diameter bolt with '5/32 " maximum sheathing 1"EWpo 1-'/8" EWp6 1-%" Lumber7 • 9 24" 28" 36" 18" 21" 36" 14" 16" 34" 12" 14" 29" 10" 12" 24" 9" 10" 21" 8" 9" 19" %" diameter bolt with 1"EWpo 24" 18" 14" 12" 10" 9" 8" 15/32 " maximum sheathin~ and %" stacked washers ,8 1-'/8" EWp6 1-%" Lumber7 ,9 28" 36" 21" 36" 16" 29" 14" 24" 12" 21" 10" 18" 9" 16" 1 The tiP of the lag screw shall fully extend beyond the inSide face of the band JOiSt. 2 The maximum gap between the face of the ledger board and face of the wall sheathing shall be V2". 3 Ledgers shall be flashed or caulked to prevent water from contacting the house band joist (see Figures 14, 15, and 16). 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 Ibs and 350 Ibs for 1" and I_lis" EWP rim board, respectively. 7 A minimum 1"x9Vz" Douglas fir-larch laminated veneer lumber rim board shall be permitted in lieu of the 2" nominal band joist. 8 Wood structural panel sheathing, gypsum board sheathing, or foam sheathing not exceeding one inch thickness shall be permitted. The maximum distance between the face of the ledger board and the face of the band joist shall be one inch. 9 Fastener spacing also applies to southern pine, Douglas fir-larch, and hem-fir band joists. American Wood Council Page 17 13 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 See Table 5 : .S N E 5.5" min. for 2)(8'" 6.5" min. for 2)(10 ~... 7.5" min. for2x12 314"min. Thru-Bolts Thru-bolts shall have a diameter of W'. Pilot holes for thru-bolts shall be 17/32" to 9/1/ in diameter. Thru-bolts require washers at the bolt head and nut. Expansion and Adhesive Anchors Use approved expansion or adhesive anchors when attaching a ledger board to a concrete or solid masonry wall as shown in Figure 15 or a hollow masonry wall with a grouted cell as shown in Figure 16. Expansion and adhesive anchor bolts shall have a diameter of Yz". SeeFi9ur~ 14fof rim JOIst fast~nerspaCing "Distance.can be reduced to 4B' iflag screws. are used or bolt spacing isredqc(:!d tothat of lag screwsJoattach 2x8 ledgers t02x8 band joists (1/2" stacked washers not permitted) Minimum spacing and embedment length shall be per the manufacturer's recommendations. All anchors must have washers. Lag Screws Lag screws shall have a diameter of Yz" (see MINIMUM REQUIREMENTS). Lag screws may be used only when the field conditions conform to those shown in Figure 14. See Figure 20 for lag screw length and shank requirements. All lag screws shall be installed with washers. Figure 20: Lag Screw Requirements Lag screw installation requirements: Each lag screw shall have pilot holes drilled as follows: 1) Drill a Yz" diameter hole in the ledger board, 2) Drill a 5/16" diameter hole into the band board of the existing house. DO NOT DRILL A W' DIAMETER HOLE INTO THE BAND BOARD. The threaded portion ofthe lag screw shall be inserted into the pilot hole by turning. DO NOT DRIVE LAG SCREWS WITH A HAMMER. Use soap or a wood compatible lubricant as required to facilitate tightening. Each lag screw shall be thoroughly tightened (snug but not over-tightened to avoid wood damage). American Forest &. Paper Association Page 18 14 PRESCRIPTIVE RESIDENTIAL WOOD DECK CONSTRUCTION GUIDE FREE-STANDING DECKS EXISTING HOUSE FOOTING IF LOCATED CLOSER THAN 5'-0" TO AN EXISTING HOUSE Decks which are free-standing do not utilize the exterior WALL (see Figure 2 and Figure 12). For houses with wall of the existing house to support vertical loads (see basements, a cylindrical footing (caisson) is Figure 21); instead, an additional beam with posts is recommended to minimize required excavation at the provided at or within L/4 ofthe existing house. THE basement wall. Beam size is determined by Table 3. ASSOCIATED DECK POST FOOTINGS SHALL BE PLACED AT THE SAME ELEVAnON AS THE Figure 21. Free-Standing Deck DECK STABILITY Decks greater than 2 feet above grade shall be provided with diagonal bracing. Figure 22. Diagonal Bracing Requirements E (1) 3/8" diameter-l '-beam _?~ 2x4, typical prpvide blocking when joil)ts do not align With posts ::l -joist ~t post focations E 'x co E thru-bolt with washers, typical BRACING PARALLEL TO BEAM BRACING PERPENOICULAR TO BEAM American Wood Council Page 19 15 PRESCRIPTIVE RESIDENTIAL WOOD DECK CONSTRUCTION GUIDE Diagonal Bracing: Provide diagonal bracing both parallel and perpendicular to the beam at each post as shown in Figure 22. When parallel to the beam, the bracing shall be bolted to the post at one end and beam at the other. When perpendicular to the beam, the bracing shall be bolted to the post at one end and a joist or blocking between joists at the other. When a joist does not align with the bracing location, provide blocking between the adjacent joists. Decks attached to the house as shown in Figure 23A do not require diagonal bracing perpendicular to the house. Diagonal bracing parallel to the house may be omitted at the beam adjacent to the house for a free-standing deck attached as shown in Figure 23. Free-standing Deck - Attachment to House: Attach the deck rim joist to the existing house exterior wall as shown in Figure 23 for a free-standing deck. The wall must be sheathed with minimum 3/8" wood structural panel sheathing. Use lag screws or thru-bolts when fastening to an existing band joist or wall stud; use expansion anchors or epoxy anchors when fastening to Figure 23. Attachment of Free-Standing Deck to House for Deck Stability exterior sheathin~ -H-II\ min. \tlickness " 3JS" '.1' / ex,sling wall stud, band _.•••_ \ joist or concrele or masonry foundalJoo wall fasteners @ Hi" o.C. ,.. " ......1II1l11"'111l staggered concrete or masonry. DO NOT ATTACH TO BRICK VENEERS. VERIFY THIS CONDITION IN THE FIELD PRIOR TO UTILIZING THIS METHOD. Fasteners shall be 16" on center and staggered in 2 rows for free-standing decks. Flashing over the rim joist is required and must be installed in accordance with the flashing provisions in the LEDGER ATTACHMENT REQUIREMENTS. Deck Supported by Ledger - Attachment to House: Where supported by attachment to an exterior wall (Figures 14, 15, or 16), decks shall be positively anchored to the primary structure and designed for both vertical and lateral loads as applicable [R502.2.2]. The lateral load connection required shall be permitted to be in accordance with Figure 23A. Hold down tension devices shall be provided in not less than two locations per deck, and each device shall have an allowable stress design capacity of not less than 1,500 Ib [R502.2.2.3]. See the Commentary to this document for additional information on applicability of this provision. Figure 23A. Example of a Lateral Load Device for a Deck Attached to a House with a Ledger floor sheathing nailing at 6' maximum on centerto joist with hold down, \-rlmjOist ..' .J\,. beam & post ••, .. ,- remove $iding al rim jOist location prior 10 installation / ... conti~uo~~ flashing oxten(ling / ' past.n•. m,.J::I.StfaSlene _lL ... I9 ~" GUARD REQUIREMENTS 24. Other methods and materials may be used for guard All decks greater than 30" above grade are required to coristruction when approved by the authority having have a guard [R312.1] - one example is shown in Figure jurisdiction. Figure 24. Example Guard Detail attacl:l to guard po!>t 'with (2]81'1 throall4,.~~., ...J stringer treads: 2x_ or 514 board treads: see Table 6 ··Kfi····· ··································/(,1 18" max III 18" max Iii 36" max ·__..__ ·~:r--·_·--·---.!AI _"'" ." / :/_ /L'J 2X4 ledgers, each side, depth of tread; attach with (4)10d threaded ''v~:, stringers ,,_./ nails or (4)#8 wood screws ~3" long the stringer span (see provisions below). If the total vertical height ofa stairway exceeds 12'-0", then an intermediate landing shall be required. All intermediate stair landings must be designed and constructed as a free-standing deck using the details in this document. Stairs shall be a minimum of 36" in width as sho\vn in Figure 33 [R31 1.7]. 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 landing shall have a minimum dimension of 36" measured in the direction of travel and no less than the width ofthe stairway served [R311.7]. Figure 28. Stair Stringer Requirements CUT STRINGER SOLID STRINGER Table 6. Minimum Tread Size for Cut and Solid Stringers1 Species Cut Stringer Solid Stringer Southern Pine 2x4 or 5/4 2x6 Douglas Fir Larch, Hem-Fir, SPF2 2x4 or 514 2x8 or 3x4 Redwood, Western Cedars, Ponderosa Pine3 , Red Pine3 2x4 or 5/4 2x10 or 3x4 1. Assumes 300 Ib concentrated load, U288 deflection limit, No. 2 grade, and wet service conditions. 2. Incising assumed for refractory species including Douglas fir larch, hem-fir, and spruce-pine-fir. CUT STRINGER SOLID STRINGER 3. Design values based on northern species with no incising assumed. American Forest & Paper Association Page 22 18 PRESCRIPTIVE RESIDENTIAL WOOD DECK CONSTRUCTION GUIDE Figure 30. Stair Guard Requirements Figure 31. Stair Stringer Attachment Detail 1-",_m,6i~t{'~~i~~~,m'--1 stair guard is required for - I; ~ /~/'r"'l" stairs with a to,tal rise of ",I,. ' /,~:I'L 30" or more; see GUARD I <'::::r:C·, '1'/ REQUIREMENTS for 1,/"", ~ :(~. ""lr I more information :<:::;~ : ~·rrJ 1• i I "C/'1' 1,./ 11'1 q I I A" ~ll/'111 I I, I.!-l I II! ~d I I *t::It=~l I I "',','''''''1: > 11 !; II ! ;~r -k i stair guard height: . 'I I ','.&' " I . 34" mi' mea"red 1L-1: ~'~I ~ from nosing of step'/ , /' ,,/~;~ r"'"r'" ' : - - - /,,/'/"/- - €), ! /,,/' ft) -1"'''''''' Openings for required guards on the-J Triangular opening shall- sides of stair treads shall not alfow not permit the passage a sphere 4-3/8" to pass through, of a 6" diameter sphere. STAIR HANDRAIL REQUIREMENTS All stairs with 4 or more risers shall have a handrail on at least one side (see Figure 32A) [R311.7.7]. The handrail height measured veliically from the sloped plane a(~ioining the tread nosing shall be not less than 34 inches and not 1110re than 38 inches (see Figure 30) [R311.7.7.11. Handrails shall be graspable and shall be composed of decay-resistant and/or corrosion resistant material. Handrails shall be Type (Type II, or provide equivalent graspability (see Figure 32B). Type I shall have a perimeter dimension of at least 4" and 110t greater Figure 32A. Handrail Mounting Examples Faslen handrails per manufacturer recommendations l~"min, T['. ~ "'\11, 11tl H ' T,~ln2 1;..r.) n 1 t' . j'-, guard handrail hardware _y_ . p o s t\rm , ". MOUNTED TO GUARD MOUNTED TO WALL \" 2x blocking 1;" min.........1~"1~¥ , "'\ T t) •34"·38" to nosing tt?\" of stairs, typical waU,- J \ .. corrosion-resistant rim joist Of-:\ outside jqist \ minimum dovmload capaCity of 625 lbs; see JOIST HANGERS for more requirements I sloped joist hanger, ATTACHMENT WITH HANGERS than 6-W'. Type II rails with a perimeter greater than 6-14" shall provide a graspable finger recess area on both sides of the profile [R311.7.7.3]. All shapes shall have a smooth surface with no sharp comers. Handrails shall run continuously from a point directly over the lowest riser to a point directly over the highest riser and shall return to the guard at each end (see Figure 33). Handrails may be interrupted by guard posts at a tum in the stair [R311.7.7.2]. Figure 328. Handrail Grip Size NONCIRCULAR CIRCULAR [R311.7. 7.3 Type !] Perimeter: 4" - sl" American Wood Council RECESSED [R31 1.7.73 Type II} Perimeter: >6l" Page 23 19 PRESCRIPTIVE RESIDENTIAL WOOD DECK CONSTRUCTION GUIDE STAIR FOOTING REQUIREMENTS [R4031 Where the stairway meets grade, attach the stringers to the stair guard posts as shown in Figure 34. Posts shall bear on footings. All footings shall bear on solid ground and sha]] be placed at least 12 inches below the undisturbed ground surhlce or below the frost line, whichever is deeper (see Figure 34). Stringers shall bear on a 2x4 bearing block attached to the post as shown. Stringers shall not bear on new or existing concrete pads or patios that are not founded below this depth. When guards are not required (see GUARD Figure 33. Miscellaneous Stair Requirements handrail shall return at each end 36" min. stair width __"---,,,,,;,{ """ """ " , , ."... ,... """".""".,.. "",f·+"",-'_'_,~ , , , , , , ( , , , to'" ... ,In'"1 I'",..J. ..,~ : ; , , . , l.. ...... J 1.". ... _ ....... ..1 REQUIREMENTS), posts may terminate below the bottom tread elevation. Bolts are only required ifa guard post is required. STAIR LIGHTING REQUIREMENTS [R303.61 Stairways shall have a light source located at the top landing such that all stairs and landings are illuminated. The light switch shall be operated from inside the house. However, motion detected or timed switches are acceptable. Figure 34. Stair Footing Detail cut post 3t bottom tread (2)Y2" diameter thru-bolts elevation when no stair with washers required only guard is required if guard is required; otherwise use (2}#8wood screws 23·%" long or(2) 16d threaded nails Attach 2x4 bearing block using '(8)#8 wood screws <;:3.%" long • _ ~18) 16dtt~.~~aded nails 4x4 post ~ r-'-J-.·-J'~'_.~ •••1._ :~ 6" = minimum ~, ,,1'00'°: '~~i~irosrd~Pth 10 x10 square or "" T 12" dia. footing , FRAMING AT CHIMNEY OR BAY WINDOW All members at a chimney or bay window shall be framed in accordance with Figure 35. Headers may span a maximum of 6'-0". When a chimney or bay window is wider than 6'_0", one or more 6x6 posts may be added to reduce header spans to less than 6'-0". In such cases, the post footing must meet the requirements in the FOOTINGS section. Headers with a span length greater than 6'-0" require a plan submission. Headers shall be located no more than 3'-0" from the end of the trimmer joist. Triple trimmer joists are required on each side of the header ifjoist spacing is 12" or 16" o.c. or ifthe trimmer joist span exceeds 8'-6"; otherwise, double trimmer joists are permitted. 'Trimmer joists may bear on the beam and extend past the beam centerline up to L.rI4 as shown in Figures 1A and 2, or the trimmer joist may attach to the side of the beam with joist hangers as shown in Figure lB. loist hangers shall each have a minimum download capacity in accordance with Table 7. Bolts or lag screws used to attach the hanger to the ledger shall fu11y extend through the ledger into the 2-inch nominal lumber band joist (l-Yz" actual) or EWP rim board. Otherwise a freestanding deck is required. Table 7. Trimmer Joist Hanger Download Capacity Joist Size Minimum Capacity, Ibs 2x8 1050 2x10 1380 2x12 1500 American Forest & Paper Association Page 24 20 tripleJoist hanger, typical (Table 7) ,,/ a := 3'-0" maximum ,-,,··,,····,,~········6·-0" maximum.~~-l ; :1 , Ii PRESCRIPTIVE RESIDENTIAL WOOD DECK CONSTRUCTION GUIDE Figure 35: Detail for Framing Around a Chimney or Bay Window r--'- decking may / extend 6" rl1aximum I . f-o--~--0"~ !_-.i"''-l I T Bolts Or lag ledger screws shall fully ext~nd into band t ~ ITI boam joist or rim board triple trimmer/ . joist each side~ \ .. double joist. hanger, typical \ double header ~ J ""-(2)Y:i' diameter1hrll-bolt or lag screws at/edger" "Trimmer joist may be double jf joists are spaced "'See Figure tefar fastenerspacing, 24" o.c. or if trimmer length is 8'-6" or less edge. and enddistaoces PLAN VIEW SECTION ·•·········· ..A'.'··.merl·can WOG'd Co··unci.···1 ~ Traditional and Engineered Wood Products 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 Forest & Paper Association 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 © 2007,2009,2010 American Forest & Paper Association, Inc. 01-10 American Wood Council
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