The design and construction of wood elements in structures using allowable stress design shall be in accordance with the following applicable standards:
| American Wood Council. | |
| NDS | National Design Specification for Wood Construction |
| SDPWS | Special Design Provisions for Wind and Seismic |
| American Institute of Timber Construction. | |
| AITC 104 | Typical Construction Details |
| AITC 110 | Standard Appearance Grades for Structural Glued Laminated Timber |
| AITC 113 | Standard for Dimensions of Structural Glued Laminated Timber |
| AITC 117 | Standard Specifications for Structural Glued Laminated Timber of Softwood Species |
| AITC 119 | Standard Specifications for Structural Glued Laminated Timber of Hardwood Species |
| ANSI/AITC A190.1 | Structural Glued Laminated Timber |
| AITC 200 | Inspection Manual |
| American Society of Agricultural and Biological Engineers. | |
| ASABE EP 484.2 | Diaphragm Design of Metal-clad, Post-Frame Rectangular Buildings |
| ASABE EP 486.2 | Shallow Post Foundation Design |
| ASABE 559.1 | Design Requirements and Bending Properties for Mechanically Laminated Columns |
| APA‒The Engineered Wood Association. | |
| Panel Design Specification | |
| Plywood Design Specification Supplement 1‒Design & Fabrication of Plywood Curved Panel | |
| Plywood Design Specification Supplement 2‒Design & Fabrication of Glued Plywood-lumber Beams | |
| Plywood Design Specification Supplement 3‒Design & Fabrication of Plywood Stressed-skin Panels | |
| Plywood Design Specification Supplement 4‒Design & Fabrication of Plywood Sandwich Panels | |
| Plywood Design Specification Supplement 5‒Design & Fabrication of All-plywood Beams | |
| EWS T300 | Glulam Connection Details |
| EWS S560 | Field Notching and Drilling of Glued Laminated Timber Beams |
| EWS S475 | Glued Laminated Beam Design Tables |
| EWS X450 | Glulam in Residential Construction |
| EWS X440 | Product and Application Guide: Glulam |
| EWS R540 | Builders Tips: Proper Storage and Handling of Glulam Beams |
| Truss Plate Institute, Inc. | |
| TPI 1 | National Design Standard for Metal Plate Connected Wood Truss Construction |
The design of rafter spans is permitted to be in accordance with the AWC STJR.
The design of plank and beam flooring is permitted to be in accordance with the AWC Wood Construction Data No. 4.
The allowable unit stresses for preservative-treated wood need no adjustment for treatment, but are subject to other adjustments.
The allowable unit stresses for fire-retardant-treated wood, including fastener values, shall be developed from an approved method of investigation that considers the effects of anticipated temperature and humidity to which the fire-retardant-treated wood will be subjected, the type of treatment and the redrying process. Other adjustments are applicable except that the impact load duration shall not apply.
The allowable unit stresses for fire-retardant-treated wood, including fastener values, shall be developed from an approved method of investigation that considers the effects of anticipated temperature and humidity to which the fire-retardant-treated wood will be subjected, the type of treatment and the redrying process. Other adjustments are applicable except that the impact load duration shall not apply.
The capacity of lumber decking arranged according to the patterns described in Section 2304.9.2 shall be the lesser of the capacities determined for flexure and deflection according to the formulas in Table 2306.1.4.
TABLE 2306.1.4 ALLOWABLE LOADS FOR LUMBER DECKING
TABLE 2306.1.4 ALLOWABLE LOADS FOR LUMBER DECKING
| PATTERN | ALLOWABLE AREA LOADa, b | |
| Flexure | Deflection | |
| Simple span |  |  |
| Two-span continuous |  |  |
| Combination simple- and two-span continuous |  |  |
| Cantilevered pieces intermixed |  |  |
| Controlled random layup | ||
| Mechanically laminated decking |  |  |
| 2-inch decking |  |  |
| 3-inch and 4-inch decking |  |  |
| For SI: 1 inch = 25.4 mm. |
| a. σb = Allowable total uniform load limited by bending. |
| σΔ= Allowable total uniform load limited by deflection. |
| b. d = Actual decking thickness. |
| l = Span of decking. |
| Fb'= Allowable bending stress adjusted by applicable factors. |
| E'= Modulus of elasticity adjusted by applicable factors. |
The allowable stress increase of 1.15 for snow load, shown in Table 2.3.2, Frequently Used Load Duration Factors, Cd, of the National Design Specifications, shall not be utilized at elevations above 5,000 feet (1,524 M).
Wood-frame diaphragms shall be designed and constructed in accordance with AWC SDPWS. Where panels are fastened to framing members with staples, requirements and limitations of AWC SDPWS shall be met and the allowable shear values set forth in Table 2306.2(1) or 2306.2(2) shall be permitted. The allowable shear values in Tables 2306.2(1) and 2306.2(2) are permitted to be increased 40 percent for wind design.
TABLE 2306.2(1) ALLOWABLE SHEAR VALUES (POUNDS PER FOOT) FOR WOOD STRUCTURAL PANEL DIAPHRAGMS UTILIZING STAPLES WITH FRAMING OF DOUGLAS FIR-LARCH, OR SOUTHERN PINEa FOR WIND OR SEISMIC LOADINGf
(continued)
TABLE 2306.2(1)‒continued ALLOWABLE SHEAR VALUES (POUNDS PER FOOT) FOR WOOD STRUCTURAL PANEL DIAPHRAGMS UTILIZING STAPLES WITH FRAMING OF DOUGLAS FIR-LARCH, OR SOUTHERN PINEa FOR WIND OR SEISMIC LOADINGf
TABLE 2306.2(2) ALLOWABLE SHEAR VALUES (POUNDS PER FOOT) FOR WOOD STRUCTURAL PANEL BLOCKED DIAPHRAGMS UTILIZING MULTIPLE ROWS OF STAPLES (HIGH-LOAD DIAPHRAGMS) WITH FRAMING OF DOUGLAS FIR-LARCH OR SOUTHERN PINEa FOR WIND OR SEISMIC LOADINGb, g, h
(continued)
TABLE 2306.2(2)‒continued ALLOWABLE SHEAR VALUES (POUNDS PER FOOT) FOR WOOD STRUCTURAL PANEL BLOCKED DIAPHRAGMS UTILIZING MULTIPLE ROWS OF STAPLES (HIGH-LOAD DIAPHRAGMS) WITH FRAMING OF DOUGLAS FIR-LARCH OR SOUTHERN PINE FOR WIND OR SEISMIC LOADING
TABLE 2306.2(1) ALLOWABLE SHEAR VALUES (POUNDS PER FOOT) FOR WOOD STRUCTURAL PANEL DIAPHRAGMS UTILIZING STAPLES WITH FRAMING OF DOUGLAS FIR-LARCH, OR SOUTHERN PINEa FOR WIND OR SEISMIC LOADINGf
| PANEL GRADE | STAPLE LENGTH AND GAGEd | MINIMUM FASTENER PENETRATION IN FRAMING (inches) | MINIMUM NOMINAL PANEL THICKNESS (inch) | MINIMUM NOMINAL WIDTH OF FRAMING MEMBERS AT ADJOINING PANEL EDGES AND BOUNDARIESe (inches) | BLOCKED DIAPHRAGMS | UNBLOCKED DIAPHRAGMS | ||||
| Fastener spacing (inches) at diaphragm boundaries (all cases) at continuous panel edges parallel to load (Cases 3, 4), and at all panel edges (Cases 5, 6)b | Fasteners spaced 6 max. at supported edgesb | |||||||||
| 6 | 4 | 21/2c | 2c | Case 1 (No unblocked edges or continuous joints parallel to load) | All other configurations (Cases 2, 3, 4, 5 and 6) | |||||
| Fastener spacing (inches) at other panel edges (Cases 1, 2, 3 and 4)b | ||||||||||
| 6 | 6 | 4 | 3 | |||||||
| Structural I grades | 11/2 16 gage | 1 | 3/8 | 2 | 175 | 235 | 350 | 400 | 155 | 115 |
| 3 | 200 | 265 | 395 | 450 | 175 | 130 | ||||
| 15/32 | 2 | 175 | 235 | 350 | 400 | 155 | 120 | |||
| 3 | 200 | 265 | 395 | 450 | 175 | 130 | ||||
| Sheathing, single floor and other grades covered in DOC PS 1 and PS 2 | 11/2 16 gage | 1 | 3/8 | 2 | 160 | 210 | 315 | 360 | 140 | 105 |
| 3 | 180 | 235 | 355 | 400 | 160 | 120 | ||||
| 7/16 | 2 | 165 | 225 | 335 | 380 | 150 | 110 | |||
| 3 | 190 | 250 | 375 | 425 | 165 | 125 | ||||
| 15/32 | 2 | 160 | 210 | 315 | 360 | 140 | 105 | |||
| 3 | 180 | 235 | 355 | 405 | 160 | 120 | ||||
| 19/32 | 2 | 175 | 235 | 350 | 400 | 155 | 115 | |||
| 3 | 200 | 265 | 395 | 450 | 175 | 130 | ||||
(continued)
TABLE 2306.2(1)‒continued ALLOWABLE SHEAR VALUES (POUNDS PER FOOT) FOR WOOD STRUCTURAL PANEL DIAPHRAGMS UTILIZING STAPLES WITH FRAMING OF DOUGLAS FIR-LARCH, OR SOUTHERN PINEa FOR WIND OR SEISMIC LOADINGf
| For SI: 1 inch = 25.4 mm, 1 pound per foot = 14.5939 N/m. |
| a. For framing of other species: (1) Find specific gravity for species of lumber in ANSI/AWC NDS. (2) For staples find shear value from table above for Structural I panels (regardless of actual grade) and multiply value by 0.82 for species with specific gravity of 0.42 or greater, or 0.65 for all other species. |
| b. Space fasteners maximum 12 inches on center along intermediate framing members (6 inches on center where supports are spaced 48 inches on center). |
| c. Framing at adjoining panel edges shall be 3 inches nominal or wider. |
| d. Staples shall have a minimum crown width of 7/16 inch and shall be installed with their crowns parallel to the long dimension of the framing members. |
| e. The minimum nominal width of framing members not located at boundaries or adjoining panel edges shall be 2 inches. |
| f. For shear loads of normal or permanent load duration as defined by the ANSI/AWC NDS, the values in the table above shall be multiplied by 0.63 or 0.56, respectively. |
TABLE 2306.2(2) ALLOWABLE SHEAR VALUES (POUNDS PER FOOT) FOR WOOD STRUCTURAL PANEL BLOCKED DIAPHRAGMS UTILIZING MULTIPLE ROWS OF STAPLES (HIGH-LOAD DIAPHRAGMS) WITH FRAMING OF DOUGLAS FIR-LARCH OR SOUTHERN PINEa FOR WIND OR SEISMIC LOADINGb, g, h
| PANEL GRADEc | STAPLE GAGEf | MINIMUM FASTENER PENETRATION IN FRAMING (inches) | MINIMUM NOMINAL PANEL THICKNESS (inch) | MINIMUM NOMINAL WIDTH OF FRAMING MEMBER AT ADJOINING PANEL EDGES AND BOUNDARIESe | LINES OF FASTENERS | BLOCKED DIAPHRAGMS | |||||||
| Cases 1 and 2d | |||||||||||||
| Fastener Spacing Per Line at Boundaries (inches) | |||||||||||||
| 4 | 21/2 | 2 | |||||||||||
| Fastener Spacing Per Line at Other Panel Edges (inches) | |||||||||||||
| 6 | 4 | 4 | 3 | 3 | 2 | ||||||||
| Structural I grades | 14 gage staples | 2 | 15/32 | 3 | 2 | 600 | 600 | 860 | 960 | 1,060 | 1,200 | ||
| 4 | 3 | 860 | 900 | 1,160 | 1,295 | 1,295 | 1,400 | ||||||
| 19/32 | 3 | 2 | 600 | 600 | 875 | 960 | 1,075 | 1,200 | |||||
| 4 | 3 | 875 | 900 | 1,175 | 1,440 | 1,475 | 1,795 | ||||||
| Sheathing single floor and other grades covered in DOC PS 1 and PS 2 | 14 gage staples | 2 | 15/32 | 3 | 2 | 540 | 540 | 735 | 865 | 915 | 1,080 | ||
| 4 | 3 | 735 | 810 | 1,005 | 1,105 | 1,105 | 1,195 | ||||||
| 19/32 | 3 | 2 | 600 | 600 | 865 | 960 | 1,065 | 1,200 | |||||
| 4 | 3 | 865 | 900 | 1,130 | 1,430 | 1,370 | 1,485 | ||||||
| 23/32 | 4 | 3 | 865 | 900 | 1,130 | 1,490 | 1,430 | 1,545 | |||||
| For SI: 1 inch = 25.4 mm, 1 pound per foot = 14.5939 N/m. |
| a. For framing of other species: (1) Find specific gravity for species of framing lumber in ANSI/AWC NDS. (2) For staples, find shear value from table above for Structural I panels (regardless of actual grade) and multiply value by 0.82 for species with specific gravity of 0.42 or greater, or 0.65 for all other species. |
| b. Fastening along intermediate framing members: Space fasteners a maximum of 12 inches on center, except 6 inches on center for spans greater than 32 inches. |
| c. Panels conforming to PS 1 or PS 2. |
| d. This table gives shear values for Cases 1 and 2 as shown in Table 2306.2(1). The values shown are applicable to Cases 3, 4, 5 and 6 as shown in Table 2306.2(1), providing fasteners at all continuous panel edges are spaced in accordance with the boundary fastener spacing. |
| e. The minimum nominal depth of framing members shall be 3 inches nominal. The minimum nominal width of framing members not located at boundaries or adjoining panel edges shall be 2 inches. |
| f. Staples shall have a minimum crown width of 7/16 inch, and shall be installed with their crowns parallel to the long dimension of the framing members. |
| g. High-load diaphragms shall be subject to special inspection in accordance with Section 1705.5.1. |
| h. For shear loads of normal or permanent load duration as defined by the ANSI/AWC NDS, the values in the table above shall be multiplied by 0.63 or 0.56, respectively. |
(continued)
TABLE 2306.2(2)‒continued ALLOWABLE SHEAR VALUES (POUNDS PER FOOT) FOR WOOD STRUCTURAL PANEL BLOCKED DIAPHRAGMS UTILIZING MULTIPLE ROWS OF STAPLES (HIGH-LOAD DIAPHRAGMS) WITH FRAMING OF DOUGLAS FIR-LARCH OR SOUTHERN PINE FOR WIND OR SEISMIC LOADING
Wood-frame shear walls shall be designed and constructed in accordance with AWC SDPWS. Where panels are fastened to framing members with staples, requirements and limitations of AWC SDPWS shall be met and the allowable shear values set forth in Table 2306.3(1), 2306.3(2) or 2306.3(3) shall be permitted. The allowable shear values in Tables 2306.3(1) and 2306.3(2) are permitted to be increased 40 percent for wind design. Panels complying with ANSI/APA PRP-210 shall be permitted to use design values for Plywood Siding in the AWC SDPWS.
TABLE 2306.3(1) ALLOWABLE SHEAR VALUES (POUNDS PER FOOT) FOR WOOD STRUCTURAL PANEL SHEAR WALLS UTILIZING STAPLES WITH FRAMING OF DOUGLAS FIR-LARCH OR SOUTHERN PINEa FOR WIND OR SEISMIC LOADINGb, f, g, i
For SI: 1 inch = 25.4 mm, 1 pound per foot = 14.5939 N/m.
TABLE 2306.3(2) ALLOWABLE SHEAR VALUES (plf) FOR WIND OR SEISMIC LOADING ON SHEAR WALLS OF FIBERBOARD SHEATHING BOARD CONSTRUCTION UTILIZING STAPLES FOR TYPE V CONSTRUCTION ONLYa, b, c, d, e
For SI: 1 inch = 25.4 mm, 1 pound per foot = 14.5939 N/m.
TABLE 2306.3(3) ALLOWABLE SHEAR VALUES FOR WIND OR SEISMIC FORCES FOR SHEAR WALLS OF LATH AND PLASTER OR GYPSUM BOARD WOOD FRAMED WALL ASSEMBLIES UTILIZING STAPLES
For SI: 1 inch = 25.4 mm, 1 foot = 304.8 mm, 1 pound per foot = 14.5939 N/m.
TABLE 2306.3(1) ALLOWABLE SHEAR VALUES (POUNDS PER FOOT) FOR WOOD STRUCTURAL PANEL SHEAR WALLS UTILIZING STAPLES WITH FRAMING OF DOUGLAS FIR-LARCH OR SOUTHERN PINEa FOR WIND OR SEISMIC LOADINGb, f, g, i
| PANEL GRADE | MINIMUM NOMINAL PANEL THICKNESS (inch) | MINIMUM FASTENER PENETRATION IN FRAMING (inches) | PANELS APPLIED DIRECT TO FRAMING | PANELS APPLIED OVER 1/2" OR 5/8" GYPSUM SHEATHING | ||||||||
| Staple sizeh | Fastener spacing at panel edges (inches) | Staple sizeh | Fastener spacing at panel edges (inches) | |||||||||
| 6 | 4 | 3 | 2d | 6 | 4 | 3 | 2 d | |||||
| Structural I sheathing | 3/8 | 1 | 11/2 16 Gage | 155 | 235 | 315 | 400 | 2 16 Gage | 155 | 235 | 310 | 400 |
| 7/16 | 170 | 260 | 345 | 440 | 155 | 235 | 310 | 400 | ||||
| 15/32 | 185 | 280 | 375 | 475 | 155 | 235 | 300 | 400 | ||||
| Sheathing, plywood sidinge except Group 5 Species, ANSI/APA PRP 210 siding | 5/16c or 1/4c | 1 | 11/2 16 Gage | 145 | 220 | 295 | 375 | 2 16 Gage | 110 | 165 | 220 | 285 |
| 3/8 | 140 | 210 | 280 | 360 | 140 | 210 | 280 | 360 | ||||
| 7/16 | 155 | 230 | 310 | 395 | 140 | 210 | 280 | 360 | ||||
| 15/32 | 170 | 255 | 335 | 430 | 140 | 210 | 280 | 360 | ||||
| 19/32 | 13/4 16 Gage | 185 | 280 | 375 | 475 | ‒ | ‒ | ‒ | ‒ | ‒ | ||
For SI: 1 inch = 25.4 mm, 1 pound per foot = 14.5939 N/m.
- For framing of other species: (1) Find specific gravity for species of lumber in ANSI/AWC NDS. (2) For staples find shear value from table above for Structural I panels (regardless of actual grade) and multiply value by 0.82 for species with specific gravity of 0.42 or greater, or 0.65 for all other species.
- Panel edges backed with 2-inch nominal or wider framing. Install panels either horizontally or vertically. Space fasteners maximum 6 inches on center along intermediate framing members for 3/8-inch and 7/16-inch panels installed on studs spaced 24 inches on center. For other conditions and panel thickness, space fasteners maximum 12 inches on center on intermediate supports.
- 3/8-inch panel thickness or siding with a span rating of 16 inches on center is the minimum recommended where applied directly to framing as exterior siding. For grooved panel siding, the nominal panel thickness is the thickness of the panel measured at the point of fastening.
- Framing at adjoining panel edges shall be 3 inches nominal or wider.
- Values apply to all-veneer plywood. Thickness at point of fastening on panel edges governs shear values.
- Where panels are applied on both faces of a wall and fastener spacing is less than 6 inches on center on either side, panel joints shall be offset to fall on different framing members, or framing shall be 3 inches nominal or thicker at adjoining panel edges.
- In Seismic Design Category D, E or F, where shear design values exceed 350 pounds per linear foot, all framing members receiving edge fastening from abutting panels shall be not less than a single 3-inch nominal member, or two 2-inch nominal members fastened together in accordance with Section 2306.1 to transfer the design shear value between framing members. Wood structural panel joint and sill plate nailing shall be staggered at all panel edges. See ANSI/ AWC SDPWS for sill plate size and anchorage requirements.
- Staples shall have a minimum crown width of 7/16 inch and shall be installed with their crowns parallel to the long dimension of the framing members.
- For shear loads of normal or permanent load duration as defined by the ANSI/AWC NDS, the values in the table above shall be multiplied by 0.63 or 0.56, respectively.
TABLE 2306.3(2) ALLOWABLE SHEAR VALUES (plf) FOR WIND OR SEISMIC LOADING ON SHEAR WALLS OF FIBERBOARD SHEATHING BOARD CONSTRUCTION UTILIZING STAPLES FOR TYPE V CONSTRUCTION ONLYa, b, c, d, e
| THICKNESS AND GRADE | FASTENER SIZE | ALLOWABLE SHEAR VALUE (pounds per linear foot) STAPLE SPACING AT PANEL EDGES (inches)a | ||
| 4 | 3 | 2 | ||
| 1/2" or 25/32" Structural | No. 16 gage galvanized staple, 7/16" crownf | 150 | 200 | 225 |
| No. 16 gage galvanized staple, 1" crownf | 220 | 290 | 325 | |
For SI: 1 inch = 25.4 mm, 1 pound per foot = 14.5939 N/m.
- Fiberboard sheathing shall not be used to brace concrete or masonry walls.
- Panel edges shall be backed with 2-inch or wider framing of Douglas Fir-larch or Southern Pine. For framing of other species: (1) Find specific gravity for species of framing lumber in ANSI/AWC NDS. (2) For staples, multiply the shear value from the table above by 0.82 for species with specific gravity of 0.42 or greater, or 0.65 for all other species.
- Values shown are for fiberboard sheathing on one side only with long panel dimension either parallel or perpendicular to studs.
- Fastener shall be spaced 6 inches on center along intermediate framing members.
- Values are not permitted in Seismic Design Category D, E or F.
- Staple length shall be not less than 11/2 inches for 25/32-inch sheathing or 11/4 inches for 1/2-inch sheathing.
TABLE 2306.3(3) ALLOWABLE SHEAR VALUES FOR WIND OR SEISMIC FORCES FOR SHEAR WALLS OF LATH AND PLASTER OR GYPSUM BOARD WOOD FRAMED WALL ASSEMBLIES UTILIZING STAPLES
| TYPE OF MATERIAL | THICKNESS OF MATERIAL | WALL CONSTRUCTION | STAPLE SPACINGb MAXIMUM (inches) | SHEAR VALUEa, c (plf) | MINIMUM STAPLE SIZE f, g |
| 1. Expanded metal or woven wire lath and Portland cement plaster | 7/8" | Unblocked | 6 | 180 | No. 16 gage galv. staple, 7/8" legs |
| 2. Gypsum lath, plain or perforated | 3/8" lath and 1/2" plaster | Unblocked | 5 | 100 | No. 16 gage galv. staple, 11/8" long |
| 3. Gypsum sheating | 1/2" × 2' × 8' | Unblocked | 4 | 75 | No. 16 gage galv. staple, 13/4" long |
| 1/2" × 4' | Blockedd Unblocked | 4 7 | 175 100 | ||
| 4. Gypsum board, gypsum veneer base or water-resistant gypsum backing board | 1/2" | Unblockedd | 7 | 75 | No. 16 gage galv. staple, 11/2" long |
| Unblockedd | 4 | 110 | |||
| Unblocked | 7 | 100 | |||
| Unblocked | 4 | 125 | |||
| Blockede | 7 | 125 | |||
| Blockede | 4 | 150 | |||
| 5/8" | Unblockedd | 7 | 115 | No. 16 gage galv. staple, 11/2" legs,15/8" long | |
| 4 | 145 | ||||
| Blockede | 7 | 145 | |||
| 4 | 175 | ||||
| Blockede Two-ply | Base ply: 9 Face ply: 7 | 250 | No. 16 gage galv. staple 15/8" long No. 15 gage galv. staple, 21/4" long |
For SI: 1 inch = 25.4 mm, 1 foot = 304.8 mm, 1 pound per foot = 14.5939 N/m.
- These shear walls shall not be used to resist loads imposed by masonry or concrete walls (see AWC SDPWS). Values shown are for short-term loading due to wind or seismic loading. Walls resisting seismic loads shall be subject to the limitations in Section 12.2.1 of ASCE 7. Values shown shall be reduced 25 percent for normal loading.
- Applies to fastening at studs, top and bottom plates and blocking.
- Except as noted, shear values are based on a maximum framing spacing of 16 inches on center.
- Maximum framing spacing of 24 inches on center.
- All edges are blocked, and edge fastening is provided at all supports and all panel edges.
- Staples shall have a minimum crown width of 7/16 inch, measured outside the legs, and shall be installed with their crowns parallel to the long dimension of the framing members.
- Staples for the attachment of gypsum lath and woven-wire lath shall have a minimum crown width of 3/4 inch, measured outside the legs.