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Typical Deck Details Page 1 Sheet 1 of 31 Inspection Services Division Typical Deck Details Based on the 2009 Virginia Uniform Statewide Building Code Page 2 Sheet 2 of 31 COVENANTS AND DEED RESTRICTIONS Many of the subdivisions and developments in Arlington County have private deed restrictions and covenants regulating the construction of decks beyond the limitations contained in the County Ordinances. These amount to contractual agreements between property owners and are enforceable through civil actions. The County does not enforce covenants and deed restrictions and is not always aware of their existence. Should you have questions about your development’s restrictions you may obtain information from your homeowner’s association or civic association. WHAT PERMITS ARE REQUIRED A building permit is required for all decks. For decks that include hot tubs, spas, etc., electrical, mechanical and/or plumbing permits are also required. WHERE TO APPLY FOR PERMITS Application for permits should be made in person at the Inspection Services Division Office, 2100 Clarendon Blvd. 10 th floor Suite 1000, Arlington Virginia, 22201 Tel: 703-228-3800 Fax: 703-228-7046 Monday through Friday, 8:00am to 5:00pm WHO CAN APPLY FOR PERMITS If a contractor is to perform the work, Arlington County strongly recommends that the contractor be the party to secure the permit. In this way, the County will be in a better position to assist the homeowner to gain compliance with codes if the work is defective. However, the property owner may secure the permit(s). WHAT IS THE COST OF PERMITS Building permit costs for the construction of a deck are calculated by the square footage based on the inspectable area; authorized by the Arlington County Inspections Services fee schedule, as approved by the Board of Supervisors. After the building permit is issued, separate fees will be charged if other permits are required based on actual equipment installed on the deck. Examples of equipment requiring additional permits include, but are not limited to, hot tubs, spas, gas grills, etc. Page 3 Sheet 3 of 31 WHAT IS REQUIRED TO OBTAIN THE PERMIT PERMIT APPLICATION A completed and signed Building Permit Application STUCTURAL PLANS Provide two copies of a structural plan The plan must be a scaled drawing showing the dimensions of your deck. The minimum acceptable scale is ¼" to 1' and must include the following information: • framing plan showing the size of all posts, joists and beams; • handrail and guardrail details; • stair details, if applicable • elevations, front, side and rear with attachment details (such as attachment to house, joist to beams, rails to posts, etc); and • footing details including location, size and depth Drawing submitted on sheets smaller than 11"x17" for will not be accepted. Please note that railings are required for any deck that will be more than 30" above grade level. The railings must be at least 36" high and have intermediate or ornamental closures that will not allow passage of an object 4 inches or more in diameter. Some building material supply stores have acceptable deck plans for sale to the public. You may use these to obtain the information listed above. A copy of the Arlington County deck details are attached for homeowner and contractor use. The typical deck details may be used to supply some of the required plan information that applies to conventional open decks. For decks with roofs, screened porches, hot tubs, or any additional loads, additional plans and details are required. PLATS Provide three copies of your House Location Plat If you do not have a copy of the House Location Plat, you can contact the Zoning Administration Office, 2100 Clarendon Blvd. 10 th floor Suite 1000, Arlington Virginia, 22201 Tel: 703-228-3883 Fax: 703-228-3896 Monday through Friday, 8:00am to 5:00pm Page 4 Sheet 4 of 31 This design document applies to single-span, single-level residential decks only. Decks whose permit drawings reference this document must be constructed in conformance with the details contained herein. A copy of this Typical Deck Details booklet must be on the job site and available to the inspector during each required inspection. Page 5 Sheet 5 of 31 guard joists post joist-to-beam connection rim joist footing guard post attachment beam ledger board attachment to existing house existing house floor construction ledger board fasteners decking post-to-beam connection General Requirements .................................................6 Decking .......................................................................6 Joists ............................................................................7 Beams ..........................................................................9 Deck Plan ..................................................................11 Joist-to-Beam Connection .........................................12 Joist Hangers .............................................................12 Posts ..........................................................................12 Footings.....................................................................14 Ledger Attachments ..................................................15 Prohibited Ledger Attachments ................................ 17 Ledger Board Fasteners ............................................ 17 Framing at Chimney or Bay Window ...................... 19 Lateral Support ......................................................... 21 Free-Standing Decks ................................................ 22 Guards ....................................................................... 22 Guard Post Attachments ........................................... 25 Stair ........................................................................... 26 Safety Glazing .......................................................... 30 Page 6 Sheet 6 of 31 GENERAL REQUIREMENTS 1. Lumber shall be southern pine, grade #2 or better and shall be ACQ, CA-B or CuN-W pressure treated. Lumber in contact with the ground shall be rated as “ground-contact.” Please note: not all treated lumber is rated for ground contact. 2. Wood-plastic composites are composed of bound wood and plastic fibers creating material that can be used as decking and guard elements as permitted herein. Permissible wood-plastic composites must bear a label indicating its performance criteria and compliance with ASTM D 7032. 3. Nails shall be ring-shanked or annular grooved. 4. Screws and nails shall be hot-dipped galvanized, stainless steel or approved for use with pressure treated lumber. 5. Hardware, e.g., joist hangers, cast-in-place post anchors, mechanical fasteners, shall be galvanized with 1.85 oz/sf of zinc (G-185 coating) or shall be stainless steel. Use products such as “Zmax” from Simpson Strong-Tie or “Triple Zinc” and “Gold Coat” from USP. 6. Decks greater than 20 sf shall have an electrical outlet along the perimeter of the deck and within 6'-6" of the surface. 7. Decks constructed in accordance with these details are not approved for privacy screens, planters, built-in seating or hot tub installations. 8. Publication DCA6 by the American Wood Council is considered equivalent to these details and can be used to obtain a permit. Go to awc.org to learn more and to download the publication. DECKING Approved Material Wood and wood-plastic composite decking shall be installed in accordance with the requirements below. Dimensions shall be 2x6 or 5/4 ("five- quarter") for wood and per manufacturer for wood-plastic composites. Wood decking may be placed at an angle of 45 to 90 degrees to the joists. Attach wood decking in accordance with FIGURE 1. Placement and attachment of wood-plastic composites shall be per manufacturer's instructions. (2)8d nails or (2)#8 screws at each joist 1 8 " typical gap wood 2x6 or 5/4 ("five quarter") board FIGURE 1: TYPICAL DECKING Page 7 Sheet 7 of 31 Wood-plastic composite label and manufacturer's instructions must be left on the jobsite for inspector verification. Plastic Decking Plastic or PVC decking, not considered a wood-plastic composite, may be substituted only when the product has a valid evaluation report from an accredited listing agency and is capable of resisting a live load of 40 PSF. Installation shall be in conformance to the evaluation report and the manufacturer's installation instructions which must be available to the inspector. JOISTS Joists shall be designed in accordance with the requirements below. Joist span is measured between the centerline of bearing at each end of the joist and does not include the overhangs. See FIGURE 2 through FIGURE 6 for joist span types. Use TABLE 1 to determine your joist size based on span length and spacing. The maximum overhang is equal to one-fourth of the length of the joist span (0.25 x joist span). Attach rim joist to end of joists as shown in FIGURE 2 and FIGURE 6. post joist hanger optional overhang existing house wall ledger board rim joist joist beam joist span overhang1 attached rim joist to ends of each joist with (3) #10 x 3" wood screws or (3) 10d nails FIGURE 2: JOIST SPAN WITH OVERHANG - DECK ATTACHED AT HOUSE beam joist hanger existing house wall joist joist hanger post beyond ledger board joist span FIGURE 3: JOIST SPAN - JOISTS ATTACHED TO SIDE OF BEAM Page 8 Sheet 8 of 31 post post rim joist joist beam beam joist span optional optional overhang1 overhang1 existing house wall 2x blocking between joists; attach with (3) 10d toe nails each side attach rim joist to ends of each joist with (3) #10 x 3" wood screws or (3) 10d nails FIGURE 4: JOIST SPAN WITH OVERHANG - DECK ATTACHED AT HOUSE beam joist hanger existing house wall joist joist hanger post beyond ledger board joist span FIGURE 5: JOIST SPAN - JOISTS ATTACHED TO SIDE OF BEAM post post rim joist joist beam beam joist span optional optional overhang1 overhang1 existing house wall 2x blocking between joists; attach with (3) 10d toe nails each side attach rim joist to ends of each joist with (3) #10 x 3" wood screws or (3) 10d nails FIGURE 6: JOIST SPAN - FREE-STANDING DECK2 1 The maximum length of the overhang is equal to one-fourth of the joist span length (0.25 x joist span). 2 For more information on Free-Standing Decks, see Sheet 22. Page 9 Sheet 9 of 31 TABLE 1: MAXIMUM JOIST SPAN LENGTH 1 Joists without Overhangs Joist Spacing→ 12" 16" 24" Joist Size↓ 2x8 13'-8" 12'-5" 10'-2" 2x10 17'-5" 15'-10" 13'-1" 2x12 18'-0" 18'-0" 15'-5" Joists with Overhangs Joist Spacing→ 12" 16" 24" Joist Size↓ 2x8 10'-6" 10'-6" 10'-2" 2x10 15'-2" 15'-2" 13'-1" 2x12 18'-0" 18'-0" 15'-5" 1 Spans are based on 40 PSF live load, 10 PSF dead load, southern pine #2, normal loading duration, wet service conditions and deflections of Δ=ℓ/360 for main span and ℓ/180 for overhang. BEAMS Beams shall be designed and assembled in accordance with the requirements below. As shown in FIGURE 7, beam span is measured between the centerlines of two adjacent posts. Beam size is determined using TABLE 2. Beams may overhang each end up to one-fourth of the beam span (0.25 x beam span) as shown in FIGURE 7. Using the members identified in TABLE 2, beams shall be assembled in accordance with FIGURE 8. Beam splices shall be located over interior post locations only. joists above post, typical beam beam splices at interior post locations only beam span beam span optional overhang1 optional overhang1 FIGURE 7: BEAM SPAN TYPES 1 The maximum length of the overhang is equal to one-fourth of the beam span length (0.25 x beam span). TABLE 2: MAXIMUM BEAM SPAN LENGTH1 Beam Size→ (2)2x6 (2)2x8 (2)2x10 (2)2x12 (3)2x6 (3)2x8 (3)2x10 (3)2x12 Joist Span↓ ≤ 6' 7'-1" 9'-2" 11'-10" 13'-11" 8'-7" 11'-4" 14'-5" 17'-5" > 6' - 8' 6'-2" 7'-11" 10'-3" 12'-0" 7'-8" 9'-11" 12'-10" 15'-1" > 8' - 10' 5'-6" 7'-1" 9'-2" 10'-9" 6'-11" 8'-11" 11'-6" 13'-6" > 10' - 12' 5'-0" 6'-6" 8'-5" 9'-10" 6'-3" 8'-1" 10'-6" 12'-4" > 12' - 14' 4'-8" 6'-0" 7'-9" 9'-1" 5'-10" 7'-6" 9'-9" 11'-5" > 14' - 16' 4'-4" 5'-7" 7'-3" 8'-6" 5'-5" 7'-0" 9'-1" 10'-8" > 16' - 18' 4'-1" 5'-3" 6'-10" 8'-0" 5'-2" 6'-7" 8'-7" 10'-1" Page 10 Sheet 10 of 31 1 Spans are based on 40 PSF live load, 10 PSF dead load, southern pine #2, normal loading duration, wet service conditions and deflections of Δ=ℓ/360 for main span and ℓ/180 for overhang with a 230 lb. point load. 16" 10d common nail or #10 wood screw, staggered in 2 rows If a beam is constructed with 3-plies, attach each outside member to the inside as shown herein 2 common nails or screws at each end and at splice ends typical fastener spacing Note: splices are permitted in multi-span beams over interior post locations only. FIGURE 8: BEAM ASSEMBLY DETAIL Page 11 Sheet 11 of 31 DECK PLAN Length to Width Ratio For decks attached to the existing house only, the ratio of the overall deck length, L, to the overall deck width, W, must be no more than 2 to 1 as shown in FIGURE 9. This requirement can also be verified by ensuring L ÷ W ≤ 2. Complete Your Deck A framing plan shows a bird's-eye view of the joist and beam layout; the location of the ledger board, diagonal bracing, posts and footings, and the type, size and spacing of the ledger board fasteners. Use the sample typical deck framing plan shown in FIGURE 9 below and the requirements herein to complete your deck. 6x6 post 2x______ rim joist 2x______ ledger board with bolts, screws, anchors @ ______" on center 2x______ joists at 12", 16" or 24" on center ______ ______ ______" round or square footing overhang (2) or (3) 2x______ beam joist hanger beam span = ______ joist span = _____ _ W = ______ L W = ______ < 2 ______ overhang overhang FIGURE 9: TYPICAL DECK FRAMING PLAN Page 12 Sheet 12 of 31 JOIST-TO-BEAM CONNECTION Each joist shall be attached to the beam as shown in FIGURE 10. Use Option 1 or Option 2 when joists bear on or overhang past the beam as shown in FIGURE 2 and FIGURE 6. Use Option 3 when joists attach to the side of the beam as shown in FIGURE 3; however, the joist depth must be less than or equal in depth to the beam depth. See Joist Hangers below for information on hanger requirements. Mechanical fasteners or hurricane clips used in Option 2 shall have a minimum capacity of 100 lbs. in both uplift and lateral load directions. See manufacturer's instructions for minimum installation requirements. beam (3) 8d toe nailed (2 on one side, 1 on the other) mechanical fastener or hurricane clip OPTION 1* joist hanger top of beam and joist must be at same elevation OPTION 2 OPTION 3 *Option 1 is prohibited on free-standing decks FIGURE 10: JOIST-TO-BEAM DETAIL JOIST HANGERS Joist hangers, as shown in FIGURE 11, shall have a minimum capacity of 600 lbs. for 2x8s, 700 lbs. for 2x10s and 800 lbs. for 2x12s. The joist hanger shall be designed and manufactured for the number of plies it is carrying. 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 framing members. Do not bend hanger flanges to accommodate field conditions. joist hanger with inside flanges FIGURE 11: TYPICAL JOIST HANGERS POSTS Deck posts shall be 6x6 with a maximum height of 14'-0" measured from the top of the footing to the underside of the beam. The beam shall be attached to the post by one of the methods shown in FIGURE 13. The attachment condition shown in FIGURE 12 is prohibited. The post cap shown in FIGURE 13, Option 2 shall be specifically designed for two- or three-ply beams and 6x6 posts with a minimum downward allowable load capacity of 5,000 lbs. Attachment shall be per manufacturer's instructions. Post caps shall be galvanized per the requirements noted on Sheet 6. Page 13 Sheet 13 of 31 Cut ends of posts shall be field treated with a wood preservative containing copper naphthenate. Such products can be found in the paint department of most hardware or home center stores. FIGURE 12: PROHIBITED POST-TO-BEAM ATTACHMENT beam must bear on 6x6 notch 2-ply beams only (2) 1 2" diameter through-bolts with washers notch post to provide beam with flush and tight bearing 6x6 post OPTION 1 OPTION 2 post cap; attachment, fasteners per manu- facturer's instructions 3-ply beams must use post cap option 6x6 post FIGURE 13: POST-TO-BEAM CONNECTION OPTIONS Page 14 Sheet 14 of 31 FOOTINGS Footings shall be constructed in accordance with the requirements below. Concrete shall be air-entrained and have a minimum compressive strength of 3,000 PSI. Footing size and thickness shall be in accordance with TABLE 3. See FIGURE 14 for post attachment options and requirements. Post anchors shall be galvanized per the requirements noted on Sheet 6. Footings shall bear on solid ground; bearing conditions must be verified by county inspectors prior to placement of concrete. Deck footings closer than 5'-0" to an existing exterior house wall must bear at the same elevation as the existing house footings. Do not construct footings over utility lines or service pipe. Call Miss Utility at 811 before you dig. TABLE 3: FOOTING SIZE Beam Span Joist Span Size of Square Size of Round Minimum Thickness 1 ≤ 10' 15" 17" 6" ≤ 8' >10' - 14' 18" 20" 8" >14' - 18' 21" 23" 9" ≤ 10' 19" 21" 8" > 8' - 12' >10' - 14' 22" 24" 10" >14' - 18' 26" 28" 11" >12' - 17' ≤ 10' 23" 25" 10" >10' - 14' 28" 30" 12" 1 The cast-in-place post base may require a footing thickness greater than the value in the table above. In such cases, the manufacturer's specified minimum footing thickness shall govern. frost depth 24" minimum grade per Table 3 pre-manufactured post base with cast-in-place post anchor footings must bear on solid ground per T able 3 posts must be centered on footing 12" diameter concrete stem per Table 3 per Table 3 per T able 3 roughen concrete joint FIGURE 14: TYPICAL FOOTING OPTIONS Page 15 Sheet 15 of 31 LEDGER ATTACHMENTS Ledger boards shall be attached to the existing house in accordance with the requirements below. The depth of a ledger board shall be greater than or equal to the depth of the joists. The attachments shall be in accordance with FIGURE 16 through FIGURE 18. The band board of the existing structure 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 a free- standing deck is required. See Free-Standing Decks on Sheet 22. Compliance with all the requirements herein is critical to ensure the safety and structural stability of your deck. Siding and Flashing Flashing shall be installed in accordance with the requirements below. The exterior finish, i.e., house siding, must be removed prior to the installation of the ledger board. Continuous flashing with a drip edge, as shown in FIGURE 16, is required at the ledger board when connected to a wood band board. Flashing shall be composed of copper (attached using copper nails only), stainless steel, UV resistant plastic or galvanized steel coated with 1.85 oz/sf of zinc (G-185 coating). Flashing at a door threshold shall be installed so as to prevent water intrusion from rain or melting ice and snow. Wood I-Joists Many homes constructed with wood I-joists, as shown in FIGURE 15, have a 1" or thicker engineered wood product (EWP) band board capable of supporting a deck; see FIGURE 16. If a minimum 1" EWP or 2x band board is not present, then a free-standing deck is required. See Free-Standing Decks on Sheet 22 for more information. FIGURE 15: WOOD I-JOIST PROFILE Page 16 Sheet 16 of 31 or wood I-joist 2x floor joist exterior sheathing joist hanger remove siding at ledger prior to installation continuous flashing with drip edge deck joist existing house stud wall 2x ledger board; must be greater than or equal to the size of the joist existing foundation wall existing 2x or 1" minimum EWP band board 1 2" diameter lag screws or through-bolts with washers, or approved wood screws FIGURE 16: ATTACHMENT OF LEDGER BOARD-TO-BAND BOARD 1 2" diameter expansion anchors with washers deck joist joist hanger existing concrete or solid masonry wall 2x ledger board; must be greater than or equal to the size of the joist to resist corrosion and decay, this area should be caulked embed anchors per manufacturer's recommendations FIGURE 17: ATTACHMENT OF LEDGER BOARD-TO- FOUNDATION WALL (CONCRETE OR SOLID MASONRY) deck joist 8" block wall 1 2" diameter approved epoxy anchors with washers joist hanger existing hollow masonry wall to resist corrosion and decay, this area should be caulked 2x ledger board; must be greater than or equal to the size of the joist minimum embed anchors per manufacturer's recommendations FIGURE 18: ATTACHMENT OF LEDGER BOARD-TO- FOUNDATION WALL (HOLLOW MASONRY) Page 17 Sheet 17 of 31 PROHIBITED LEDGER ATTACHMENTS The ledger board attachment conditions shown FIGURE 19 through FIGURE 21 below are strictly prohibited. In such cases the deck shall be free-standing. See FREE-STANDING DECKS on Sheet 22. house floor trusses deck joist FIGURE 19: FLOOR TRUSSES joist deck brick veneer or masonry chimney FIGURE 20: BRICK VENEER overhang or bay window FIGURE 21: HOUSE OVERHANG LEDGER BOARD FASTENERS Ledger board fasteners shall be installed in accordance with FIGURE 22 and the on center spacing in TABLE 4. Only those fastener types noted herein are approved for use. Adequacy of connections will be verified by county inspectors. typical spacing interior fasteners; 2 rows staggered1 NO LEAD ANCHORS 51 2" min. for 2x8 61 2" min. for 2x10 71 2" min. for 2x12 4 fasteners, each end of ledger board 2" 2" min. sides, top & bottom edges 2" FIGURE 22: LEDGER BOARD FASTENER SPACING AND CLEARANCES 1 Additional interior fasteners are required at chimney or bay window; see FIGURE 24. TABLE 4: LEDGER BOARD FASTENER SPACING, ON CENTER Page 18 Sheet 18 of 31 Joist Span→ ≤6' >6'-8' >8'-10' >10'-12' >12'-14' >14'-16' >16'-18' Fastener↓ Band Board↓ Lag Screws EWP 1 24" 18" 14" 12" 10" 9" 8" 2x lumber 30" 23" 18" 15" 13" 11" 10" Through Bolts EWP 1 24" 18" 14" 12" 10" 9" 8" 2x lumber 36" 36" 34" 29" 24" 21" 19" Approved Wood Screws 2 1" EWP 1 18" 13" 11" 9" 8" 7" 6" 2x lumber 19" 14" 11" 9" 8" 7" 6" Expansion Anchors - 36" 36" 34" 29" 24" 21" 19" Approved Epoxy Anchors - 32" 32" 32" 24" 24" 16" 16" 1 EWP = 1" minimum manufactured engineered wood product; see Sheet 15 for more information. 2 Wood screws shall be permitted to be spaced according to the product’s valid and current ICC-ES evaluation report. Through-Bolts Through-bolts shall have a minimum diameter of 1 /2". Pilot holes for through-bolts shall be 17 /32" to 9 /16" in diameter. Through-bolts must be equipped with washers at the bolt-head and nut. Expansion Anchors Use expansion anchors when attaching a ledger board to a concrete or solid masonry wall as shown in FIGURE 17. Bolt diameters of the anchors shall be a minimum of 1 /2"; in some cases, this may require an anchor size of 5 /8". Expansion anchors must be installed in accordance with manufacturer's specifications. Epoxy Anchors When attaching to concrete, solid masonry or hollow masonry, use one of the approved epoxy anchors listed in TABLE 5 with a minimum diameter of 1 /2". Installation shall be in conformance to the manufacturer's instructions and as shown in FIGURE 18 for hollow masonry. Epoxy cartridges must be remain on the jobsite until inspector approval. TABLE 5: APPROVED EPOXY ANCHORS Manufacturer Product ITW Ramset/Red Head Epcon Acrylic 7 Hilti HY-20 Lag Screws Lag screws shall be installed in accordance with the requirements below. The minimum diameter shall be 1/2". Lag screws shall be hot-dipped galvanized or stainless steel. Lag screws may be used only when the field conditions match those shown in FIGURE 16. See FIGURE 23 for lag screw length and shank requirements. Page 19 Sheet 19 of 31 stainless steel only dipped galvanized or lag screws must be hot- existing band board length must extend through (no threads) 1 2 " dia. 11 2" shank screw must penetrate beyond band board a minimum of 1 2" FIGURE 23: LAG SCREW REQUIREMENTS Lag screws shall be installed with washers. Each lag screw shall have pilot holes drilled as follows: 1) Drill a 1/2" diameter hole in the ledger board 2) Drill a 5/16" diameter hole into the solid connection material of the existing house; do not drill a 1/2" diameter hole. The threaded portion of the lag screw shall be inserted into the pilot hole by turning. Do not drive with a hammer. Use soap or a wood-compatible lubricant as required to facilitate tightening. Each lag screw shall be thoroughly tightened snug, but shall not be overly tightened so as to cause wood damage. Wood Screws Use the wood screws listed in TABLE 6 with a 1 /4" diameter and a sufficient length to fully penetrate the existing house band board. Installation shall be in conformance with the manufacturer's instructions. TABLE 6: APPROVED WOOD SCREWS Manufacturer Product FastenMaster LedgerLok Simpson Strong-Tie Strong-Drive Screws (SDS, SDW) Page 20 Sheet 20 of 31 FRAMING AT CHIMNEY OR BAY WINDOW All framing at a chimney or bay shall be constructed in accordance with FIGURE 24 and the requirements below. Header size shall be equal to the joist size. When the chimney or bay window is deeper than 3'-0", install a 6x6 post with footing per the requirements on Sheet 14 below each triple joist at the location of the header connection. When the header is longer than 6'-0", install 6x6 posts with footing per the requirements on Sheet 14 below the header to reduce the span to less than 6'-0". Post footings must meet the requirements on Sheet 14. Joist hangers shall be specifically designed to accommodate the number of members identified in FIGURE 24. PLAN VIEW SECTION decking may extend 6" maximum 3' m ax. Note: joist hangers shall be sized for the number of plies supported 3-ply1 joist, each side 3-ply1 joist 2 ledger board interior fasteners on each side of chimney or bay window2 6'-0" maximum chimney or bay window ledger board ledger board 2-ply header chimney or bay window FIGURE 24: REQUIREMENTS FOR FRAMING AT CHIMNEY OR BAY WINDOW 1 May be reduce to 2-ply joists if joist spacing = 24" on center, joist span ≤ 8'-6" or chimney/bay window depth ≤ 18". 2 Fasteners adjacent chimney/bay window are considered interior to the ledger board. See FIGURE 22 for fasteners requirements at the end of the ledger board. Page 21 Sheet 21 of 31 LATERAL SUPPORT All decks greater than 4'-0" above grade shall resist lateral loading by providing diagonal bracing as shown in FIGURE 25 and in accordance with the following: Diagonal bracing shall be 2x4 minimum. Decks shall have diagonal bracing installed at beam locations. Free-standing decks shall also have diagonal bracing installed parallel to joists at each post location in accordance with FIGURE 26. Only one type of diagonal bracing shall be provide in each beam line as identified in FIGURE 25 and each joist line as identified in FIGURE 26. Connection of diagonal bracing shall be in accordance with FIGURE 27. 2' 2' KNEE BRACING place knee bracing at all beam- post locations K-BRACING place k-bracing in two adjacent bays k-bracing is prohibited in single bay decks X-BRACING place x-bracing in alternating bays FIGURE 25: DIAGONAL BRACING AT BEAM-POST LOCATIONS (all decks) 2' 2' KNEE BRACING place knee bracing at all joist-post locations align joists to accommodate bracing connection at post K-BRACING k-bracing shall be attached at the midspan of the joist align joists to accommodate bracing connection at post X-BRACING provide blocking behind joist to align connection align joists to accommodate bracing connection at post FIGURE 26: DIAGONAL BRACING AT JOISTS-POST LOCATIONS (free-standing decks only) Page 22 Sheet 22 of 31 AT JOIST OR BEAM bracing, back of post bracing, front of post 1 2" diameter through- bolt with washer, typical AT POST-BEAM CONNECTION AT BOTTOM OF POST joist or beam bracing, back of post FIGURE 27: TYPICAL CONNECTIONS OF DIAGONAL MEMBERS FREE-STANDING DECKS Decks which are free-standing do not utilize the exterior wall of the existing house to support vertical loads. Instead, an additional beam with posts is provided at or offset from the existing house; see FIGURE 6. When the edge of the deck footings are closer than 5'-0" to an existing exterior house wall, it must bear at the same elevation as the existing house footings, see FIGURE 28 below. Beam size is determined by TABLE 2. joist overhang 2x blocking joists rim joist beam, posts existing house foundation wall < 5'-0", footings must be at same elevation as existing house footing diagional bracing FIGURE 28: FREE-STANDING DECK Page 23 Sheet 23 of 31 GUARDS Guards, whether required or not, shall be constructed in accordance with the requirements on the proceeding pages and figures. Deviations are prohibited. When Required When a deck is greater than 30" above grade at a point 36" from the edge of the deck, as shown in FIGURE 29, a guard is required. Wood-Plastic Composites Wood-plastic composites of the same dimensions and complying with the criteria noted on Sheet 6 may be substituted for the guard rail-cap and infill elements shown in FIGURE 30 provided the manufacturer’s performance criteria specifically allow it. 36" >30 " deck floor elevation grade elevation point edge of deck FIGURE 29: WHEN A GUARD IS REQUIRED Guard Systems Pre-fabricated systems composed of wood, wood-plastic composites or plastic purchased from a home center store, lumber company or similar will require a plan submission during the permit application process. Only guard systems with a valid evaluation report from an accredited listing agency will be approved for installation. 2x4 top and bottom; may be placed on either side of guard post; attach to post with (2) 8d ring-shank nails or (2) #8 wood screws (2) 1 2" diameter through-bolts and washers 36" DO NOT NOTCH 4x4 post, typical minimum 6'-0" maximum spacing openings shall not allow the passage of a 4" diameter sphere; wet lumber must be spaced such that when shrinkage occurs, the maximum opening is maintained rail cap: 2x6, 5/4 board or approved manufactured material attach pickets at top and bottom with (1) #8 wood screw or (2) 8d ring-shank nails with a 0.135" nominal diameter 2x2 pickets; may be placed on either side of guard FIGURE 30: TYPICAL GUARD DETAIL Page 24 Sheet 24 of 31 do not notch guard post at deck connection FIGURE 31: NOTCHING AT GUARD POSTS outside joist or rim joist 2" minimum centerline of guard post 2" minimum (2) 1 2" diameter through-bolts and washers 2 1 2 " min . 5" ma x. FIGURE 32: GUARD POST ATTACHMENT DETAIL Page 25 Sheet 25 of 31 GUARD POST ATTACHMENTS Guard posts must be attached in accordance with the requirements below. Guard posts must be fastened to the framing in order to ensure the entire guard can resist imposed loads. Hold-down anchors, as shown in FIGURE 33 and FIGURE 34, shall be used to attach the guard post to the outside joist and rim joist, respectively. Hold-down anchors shall have an 1,800 lb. minimum capacity and shall be galvanized per the requirements on Sheet 6. Guard posts may be attached to either side of the rim joist or outside joist. PLAN VIEW SECTION outside-joist outside-joist guard post at first interior bay, provide 2x blocking at guard posts; toe nail with 10d nails top and bottom, each side blocking hold-down anchor, typical guard post fasteners and attachment per hold-down manufacturer FIGURE 33: GUARD POST-TO-OUTSIDE JOIST DETAIL hold-down anchor between joists at joist location align guard post at joist locations fasteners and attachment per hold-down manufacturer hold-down anchor joist rim joist rim joist SECTION PLAN VIEWS guard post rim joist guard post hold-down anchor joists FIGURE 34: GUARD POST-TO-RIM JOIST DETAIL Page 26 Sheet 26 of 31 STAIRS Stair Geometry Stairs shall be a minimum of 36" in width as shown in FIGURE 42. Tread, riser and nosing dimensions, opening limitations and tolerance minimums shall meet the requirements shown in FIGURE 35. Tread & Riser Material Tread and riser material shall be in accordance with the requirements below. Tread material shall be equivalent to decking as specified on Sheet 6. Wood-plastic composites may not have capacity for stair treads equal to their wood equivalents. 2x wood material shall be used on 36" wide stairs framed with two stringers only. See Sheet 26 for more information. Tread material shall be attached per FIGURE 38. Risers may be framed with 1x lumber minimum or equivalent wood-plastic composite. 81 4" maximum riser; height shall not deviate from one another by more than 3 8" 3 4" - 11 4" nosing; nosing shall not deviate from one another by more than 3 8" riser may be open, but shall not allow the passage of a 4" diameter sphere riser tread tread width 9" minimum FIGURE 35: TREAD AND RISER DETAIL Stair Stringers Stringers shall be constructed in accordance with the following requirements. Stringers shall be sawn or solid 2x12s meeting the stair geometry requirements shown in FIGURE 35. Attach stringers to the deck per FIGURE 37. Stringers shall be spaced at a maximum of 18" on center. However, stairs with a width equal to 36" may be constructed with two stringers provided the treads are comprised of wood 2x material only. Measured horizontally, the maximum horizontal stringer spans shall not exceed the lengths shown in FIGURE 36. Stringers with long spans may be supported with 4x4 posts along their length to create multiple compliant spans. The 4x4 post shall be notched and bolted to the stringer with (2) 1/2" diameter through-bolts with washers per FIGURE 13, Option 1. The post shall be centered on a 10" diameter or 8" square, 4" thick footing 12" below grade and be attached per FIGURE 14. Intermediate landings may also be provided to shorten the stringer span; see Stair Landings on Sheet 27. Page 27 Sheet 27 of 31 SAWN STRINGER maximum span = 7'-0" maximum span = 16'-6" SOLID STRINGER 5" minimum FIGURE 36: STAIR STRINGER REQUIREMENTS sloped joist hanger; see Joist Hangers for more requirements solid, single rim joist or outside joist FIGURE 37: STAIR STRINGER ATTACHMENT DETAIL stringer SOLID STRINGER tread CUT STRINGER stringer attach tread material with (2) #8 screws or (2) 8d nails per board at each stringer or ledger tread 2x4 ledger, each side, full depth of tread; attach with (4)10d nails or (4)#8 screws 18" 18" 36" maximum FIGURE 38: TREAD CONNECTION REQUIREMENTS Stair Landings If the total vertical height of a stairway exceeds 12'-0", then an intermediate landing will be required. Intermediate stair landings shall be designed and constructed as a free-standing deck using the details herein. However, for stair landings only, 4x4 posts may be used in lieu of 6x6 posts for heights less than or equal to 7'- 0". Every landing shall have a minimum dimension of 36" measured in the direction of travel and not less than the width of the stairways served. Page 28 Sheet 28 of 31 between posts 6'-0" maximum diameter sphere permit the passage of a 6" triangular opening shall not 34" measure from stair guard height: nosing of step stair guard is required for stairs with a total rise more than 30" at a point 36" from the edge of the stair; see Guard Requirements for more information provide blocking between stair stringers at guard post locations; toe nail with 10d nails top and bottom, each side guard post FIGURE 39: STAIR GUARD REQUIREMENTS Stair Handrails Handrails shall be constructed in accordance with the following requirements. Stairs with four or more risers shall have a handrail on one side. Handrails shall be graspable per FIGURE 40. Handrail and connecting hardware material shall be decay-resistant and/or corrosion resistant. Handrail shall be attached to the stair guard or an existing exterior wall which acts as a barrier to the stairs. See FIGURE 41. All shapes shall have a smooth surface with no sharp corners. Recessed sections may be shaped from a 2x6 or 5/4 board. 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 42. Handrails may be interrupted by guard posts only at a turn in the stair. 11 4" - 23 4" min. 3 4 " max . min. 1 3 4 " min. 11 4" - 2" Perimeter: 4" - 61 4" 2 1 4 " max. CIRCULAR RECESSED NONCIRCULAR max . 7 8 " 3 8 " 5 16" Perimeter > 61 4" FIGURE 40: HANDRAIL GRASPABILITY TYPES/GEOMETRY Page 29 Sheet 29 of 31 attach blocking, handrail to guard with 8d nails @ 16" o.c. MOUNTED TO GUARD MOUNTED TO WALL 34"-38" to nosing of stairs, typical wall guard post 13 4" min. 13 4" min. 2x blocking 11 2" min. corrosion-resistant handrail hardware 11 2" min. 11 2" min. FIGURE 41: HANDRAIL REQUIREMENTS 36" min. stair width handrail han drail heigh t: nosing of ste p 34"-38 " from handrail shall return at each end all stairs and landings must be illuminated; see Stair Lighting FIGURE 42: MISCELLANEOUS STAIR REQUIREMENTS Stair Lighting Stairways shall have a light source located at the top landing such that all stairs and landings are illuminated. Lights shall be operated from switches inside the house, motion detectors or timed switches. Page 30 Sheet 30 of 31 Stair Stringer Footings Stair stringers at grade shall bear on a concrete footing as shown in FIGURE 43. The footings for each stringer may be combined and poured as a 12" deep slab. stringer 8" square or 10" round, 12" deep footing stringer guard post FIGURE 43: STAIR STRINGER FOOTING SAFETY GLAZING To reduce injury due to an accidental impact, safety glazing in window and door glass is required when the existing house wall encloses any portion of the deck or acts as a barrier to adjacent stairs, landings and the areas at the top and bottom of the stairs. Glazing shall be located in the affected panes of the areas identified below. Adjacent surface of deck: individual panes wholly located in the area identified in FIGURE 44 with a total pane area greater than 9 sf. Adjacent stairway: individual panes partially or wholly located in the area shown in FIGURE 45. glass panes wholly within this area and more than 9 sf must be safety glazed 36" 18" walking surface of deck FIGURE 44: SAFETY GLAZING AREA AT WALKING SURFACE Page 31 Sheet 31 of 31 60" 36" 60" 60" glass panes, partially or wholly, within this area adjacent stairs must be safety glazed walking surface of deck lower walking surface FIGURE 45: SAFETY GLAZING AREA AT STAIRS
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