Section 321.25. Wood frame walls.

  Unless designed through structural analysis, wood frame walls shall comply with the following requirements.

(1)   Stud configuration. Wood studs shall comply with the size and spacing requirements indicated in Table 321.25-A. Studs in the exterior walls shall be placed with the wide faces perpendicular to the plane of the wall.

(2)   Top plates.

(a) General. Except as allowed under subd. 3. , top plates shall be provided and configured as follows:

1. Studs at bearing walls shall be capped with double top plates.

2. End joints in double top plates shall be offset at least 2 stud spaces.

3. Double top plates shall be overlapped at the corners and at intersections of partitions.

4. The plate immediately above the stud may have a joint only when directly over the stud.

(b) Notching and boring.

1. When piping or ductwork is placed in an exterior wall or an interior load-bearing wall, such that at least half of the top plate is removed, the plate shall be reinforced with a steel angle at least 2 inches by 2 inches by 20 gauge thick.

2. The steel angle shall span the gap and extend at least to the midpoint of the adjacent stud spaces.

3. Other equivalent materials may be used in accordance with s. SPS 321.02 .

(c) Exceptions.

1. A single top plate may be used in place of a double top plate provided a rafter is located directly over the studs and the plate is securely tied at the end joints, corners and intersecting walls. Joints may occur in single top plates only when directly over a stud.

2. A continuous header, consisting of two 2-inch members set on edge, may be used in lieu of a double plate if tied to the adjacent wall.

(2m)   Bottom plates.

(a) Masonry foundation walls with open top course.

1. Where a masonry foundation wall has an open top course, a bottom plate at least as wide as the foundation wall shall be fastened to the foundation.

2. Where anchor bolts are used on a masonry foundation wall with an open top course, the minimum width of an individual piece making up the bottom plate shall be at least 5 1/2 inches.

(b) Extension beyond the bearing surface. All of the following requirements apply to a sawn-lumber sill plate with uniform loading that is partially extended beyond the load-bearing surface of a foundation wall in order to put the exterior surface of an upper-lying wall flush with or beyond the exterior surface of insulation which is placed on the outside of the foundation wall:

1. The center of any anchor bolt shall be set back from the side edge of the sill plate by a distance of at least 4 times the diameter of the bolt.

2. The thickness of the concrete or mortar cover around any anchor bolt shall comply with ACI 318 section 7.7.

3. Where a stud wall bears directly on a double bottom plate, the plate may not extend more than 1 1/2 inches beyond the load-bearing surface of the foundation wall.

4. Where a stud wall bears directly on a single bottom plate, the plate may not extend more than 1 inch beyond the load-bearing surface of the foundation wall.

(3)   Wall openings.

(am) Headers. Where doors or windows occur, headers shall be used to carry the load across the opening.

(bm) Header size. The size of headers shall be determined in accordance with the spans and loading conditions listed in Tables 321.25-B, 321.25-C and 321.25-D. Headers for longer spans shall be designed by an engineering method under s. SPS 321.02 .

(cm) Header support. Headers in bearing walls shall be supported in accordance with subd. 1. or 2. or 3.

1. Headers 3 feet or less in length shall be directly supported on each end by either:

a. The single common stud and a shoulder stud; or

b. The single common stud with a framing anchor attached.

2. Headers greater than 3 feet but less than or equal to 6 feet in length shall be directly supported on each end by the single common stud and a shoulder stud.

3. Headers greater than 6 feet in length shall be directly supported on each end by the single common stud and 2 shoulder studs.

(4)   Notching. Notching and boring of columns or posts is prohibited unless designed through structural analysis. Studs shall not be cut or bored more than 1 / 3 the depth of the stud, unless the stud is reinforced.

(5)   Partitions. Load-bearing partitions shall be placed over beams, girders, or other load-bearing partitions. Load-bearing partitions running at right angles to the joists shall not be offset from the main girder or walls more than the depth of the joist unless the joists are designed to carry the load.

(6)   Posts and columns.

(a) General.

1. Posts and columns shall be installed to resist imposed loads.

2. Posts and columns shall bear directly over the middle 1 / 3 of a footing.

3. Posts and columns shall be restrained at the top and bottom to resist displacement.

4. All columns shall be positively attached to the beams they support using clips, straps or saddles.

5. Posts and columns that use a height adjustment mechanism shall have the mechanism imbedded in concrete or permanently disabled after installation.

(b) Bearing surface. Posts and columns shall have a steel bearing plate affixed to one or both ends to distribute any applied loads and to prevent fiber crushing of any structural member being supported.

(c) Steel posts or columns. Steel posts or columns shall be sized according to one of the following methods:

1. Manufactured columns shall follow the manufacturer's testing and listing. - See PDF for table

2. Columns made solely of steel pipe stock shall follow Table 321.25-E.

3. Columns made of steel stock, not meeting the requirements of subd. 1. or 2. , shall follow a nationally accepted design specification or the size shall be determined through structural analysis or load testing.

(d) Wood posts or columns. Wood posts or columns shall be sized according to Table 321.25-F or the size shall be determined through structural analysis or load testing. - See PDF for table - See PDF for table - See PDF for table

(7)   foundation cripple walls.

(a) Foundation cripple walls shall be framed with studs at least as large as the studs above.

(b) When more than 4 feet in height, cripple walls shall be framed with studs needed for an additional floor level.

(c) Cripple walls with a stud height of less than 14 inches shall be sheathed on at least one side for its entire length with a wood structural panel that is fastened to both the top and bottom plates or the cripple walls shall be constructed of solid blocking.

(d) Cripple walls with a stud height of 14 inches or greater shall be braced in accordance with sub. (8) .

(e) Cripple walls shall be fully supported by a continuous foundation.

(8)   Wall bracing.

(a) General. Dwellings using wood-framed walls shall be braced in accordance with this section. Where a building, or a portion thereof, does not comply with one or more of the bracing requirements in this section, those portions shall be designed and constructed in accordance with accepted engineering practice.

(b) Bracing Materials and Methods. Wall bracing shall consist of the materials and methods listed in Table 321.25–G or approved alternatives capable of providing the required wind load resistance as determined in accordance with s. SPS 321.02 (1) (c) . - See PDF for table - See PDF for table

(c) Bracing amount. Bracing methods and materials complying with Table 321.25–G shall be applied to walls in accordance with all of the following requirements:

1. For the purpose of determining bracing amounts, the outermost extents of the building plan at each floor level shall be circumscribed with a rectangle to define the overall length of each building side as shown in Figure 321.25–B.

2. In no case may the amount of bracing be less than two braced wall panels on walls parallel to each rectangle side for each floor level of the building.

3. Where used, the number of intermittent brace panels applied to walls parallel to each rectangle side shall comply with Table 321.25–I.

4. Where used, the total length of continuous sheathed brace panels applied to walls parallel to each building side shall comply with Table 321.25–J.

5. The location of brace panels applied to walls parallel to each building side shall comply with Figure 321.25–C.

6. Balloon-frame walls may be no longer than 21 feet and shall have a maximum height of two floors unless constructed in accordance with an approved design. Wall framing shall be continuous from the lowest floor to the wall top plate at the roof. All edges of sheathing shall be supported on and fastened to blocking or framing. Braced wall panels may not be required on the balloon-frame wall portion provided the bracing amount and brace spacing requirement are satisfied for the building side. Where brace panels are located on the balloon-frame wall portion, they shall have a height-to-width ratio of not more than 2.5:1.

7. For a gable end wall, if the brace-panel height does not exceed 12 feet at the highest portion and if the 12 ½ -foot and 21-foot spacing requirements in Figure 321.25–C are met, the wall is adequately braced. Where a brace panel exceeds 12 feet in height, it shall have a height-to-width ratio of not more than 2.5:1, and comply with Figure 21.25–C.

(d) Braced wall panel support. Braced wall panels shall be supported on floor framing or foundations as follows:

1. Where joists are perpendicular to braced wall lines above or below, blocking shall be provided between the joists at braced wall panel locations to permit fastening of wall plates in accordance with the fastener table in the ch. SPS 325 Appendix A .

2. Where joists are parallel to braced wall lines above or below, a rim joist or other parallel framing member shall be provided at the wall to permit fastening of wall plates in accordance with the fastener table in the ch. SPS 325 Appendix A .

3. Braced wall panels shall be permitted to be supported on cantilevered floor joists meeting the cantilever limits of s. SPS 321.22 (6) provided joists are blocked at the nearest bearing wall location, except such blocking is not required for cantilevers not exceeding 24 inches where a full height rim joist is provided.

Cr. Register, November, 1979, No. 287 , eff. 6-1-80; cr. (1) (d) and am. (3) (b), Register, February, 1985, No. 350 , eff. 3-1-85; r. and recr. (3) (b), am. Table 21.25 B and E, Register, January, 1989, No. 397 , eff. 2-1-89; am. (3) (a) and (6), Register, March, 1992, No. 435 , eff. 4-1-92; r. and recr. (1) (c), am. Table 21.25-D, cr. Table 21.25-F, Register, November, 1995, No. 479 , eff. 12-1-95; am. Table 21.25-A, Register, January, 1999, No. 517 , eff. 2-1-99; r. (1) (b) and (c), renum. (1) (d) to be (b), r. and recr. (2), (6) and Tables 21.25-E and F, and am. (3) (b) 3., Register, March, 2001, No. 543 , eff. 4-1-01; CR 02-077 : r. (3) (c) Register May 2003 No. 569 , eff. 8-1-03; CR 08-043 : am. (1) (title), r. (1) (b), renum. (1) (a) and (6) (a) 4. to be (1) and (6) (a) 5., r. and recr. Table 21.25-A, cr. (6) (a) 4., (7), (8) and (9) Register March 2009 No. 639 , eff. 4-1-09; correction in Figure 21.25-E made under s. 13.92 (4) (b) 7. , Stats., Register March 2009 No. 639 ; CR 09-104 : am. 21.25 (8) (e) 2., Table 21.25-H, (9) (b) 3., Table 21.25-J, Figure 21.25-G (c), (9) (c) 4. Register December 2010 No. 660 , eff. 1-1-11; correction in (1), (2) (b) 3., (3) (a), (6) (c) 2., (d), (8) (c) 1. d., 2. c., (d), (e) 2., 3., (f) 2., (g) 3., (h) 2. b., (9) (b) 1., 2. b., d., 4. b., c., i., (c) 2. (intro.), b., c., d., 3., 4., 5. a., c., d., g., h., i., Table 321.25-H, Figure 321.25-F, -H to -K made under s. 13.92 (4) (b) 7. , Stats., Register December 2011 No. 672 ; EmR1403 : emerg. am. Table 321.25-A, (7) (d), r. and recr. (8) (b), (c), Tables 321.25-G to 321.25-J, Figures 321.25-A to 321.25-C, r. (8) (d) to (f), renum. (8) (g) (title), (intro.), 1. to 3. to (8) (d) (title), (intro.), 1. to 3., r. (8) (g) 4., (h), (9), Tables 321.25-K, 321.25-L, Figures 321.25-D to 321.25-K, eff. 4-1-14; CR 14-015 : am. Table 321.25-A, (7) (d), r. and recr. (8) (b), (c), Tables 321.25-G to 321.25-J, Figures 321.25-A to 321.25-C, r. (8) (d) to (f), renum. (8) (g) (title), (intro.), 1. to 3. to (8) (d) (title), (intro.), 1. to 3., r. (8) (g) 4., (h), (9), Tables 321.25-K, 321.25-L, Figures 321.25-D to 321.25-K Register August 2014 No. 704 , eff. 9-1-14; CR 15-041 : cr. (2m), renum. (3) (intro.), (a), (b) to (3) (am), (bm), (cm), cr. (3) (am) (title), am Table I (title), Table J (title) Register December 2015 No. 720 , eff. 1-1-16; CR 15-043 : am. (8) (d) 1., 2. Register December 2015 No. 720 , eff. 1-1-16.

Note

See ch. SPS 325 Appendix A for acceptable nailing schedule. Microsoft Windows NT 6.1.7601 Service Pack 1 See s. SPS 321.10 for requirements on treating wood for decay and termite resistance. Microsoft Windows NT 6.1.7601 Service Pack 1 20 gauge is approximately 0.036 inch. Microsoft Windows NT 6.1.7601 Service Pack 1 A sill plate can be made of multiple pieces to achieve the full width. Microsoft Windows NT 6.1.7601 Service Pack 1 Under ACI 318 section 7.7, the minimum cover for a 5/8-inch-diameter or smaller bolt is 1 1/2 inches. Microsoft Windows NT 6.1.7601 Service Pack 1 A 3-story frame house with walls constructed of 2 x 4 standard grade studs would require a 12-inch stud spacing on the lowest level, a 24-inch stud spacing on the intermediate level, and a 24-inch stud spacing on the upper level. Microsoft Windows NT 6.1.7601 Service Pack 1 *These tables are based on wood with a fiber bending stress of 1,000 psi. For other species with different fiber bending stresses, multiply the span by the square root of the ratio of the actual bending stress to 1,000 psi. Example: From Table 321.25-B, the allowable roof/ceiling span for a 28-foot wide house in zone 2, using two 2 x 8 header members with a 1400 psi bending stress, is 5 feet - See PDF for diagram = 5.9 feet. - See PDF for table - See PDF for table Microsoft Windows NT 6.1.7601 Service Pack 1 This Table is based on a modulus of elasticity or E of 1,000,000 psi and a fiber bending strength or F b of 1,000 psi. Microsoft Windows NT 6.1.7601 Service Pack 1 Acceptable engineering wall bracing practices include any of the following: Microsoft Windows NT 6.1.7601 Service Pack 1 1. The provisions under section R602.10 or R602.12 of the International Residential Code (IRC) – 2012. Microsoft Windows NT 6.1.7601 Service Pack 1 2. Design in accordance with the engineering basis of the 2012 IRC bracing provisions, such as described in Crandell, J. and Martin, Z., "The Story Behind the 2009 IRC Wall Bracing Provisions (Part 2: New Wind Bracing Requirements)," Wood Design Focus , Forest Products Society, Peachtree Corners, GA, Spring 2009. Microsoft Windows NT 6.1.7601 Service Pack 1 3. Installation instructions from the manufacturer of the bracing product that are compliant with s. SPS 321.02 . Microsoft Windows NT 6.1.7601 Service Pack 1 For a walk-out basement where some of the walls are concrete and other walls or portions thereof are wood-framed, the Department considers a minimum 8-inch-nominal-thickness?poured-in-place concrete basement wall as being equivalent in lateral load and shear resistance to any of the allowable wood-framed wall bracing materials. To determine the required bracing for a walk-out basement, first draw a rectangle around the entire floor plan and projections as if all of the walls are wood-framed. Determine the required bracing amounts per the chosen bracing material and method and then locate the bracing to meet the requirements of Figure 321.25-C. Any required braced wall panel locations that occur on a wall or portion of a wall that is actually of poured-in-place concrete construction is considered equivalent, and that amount of bracing will count towards the minimum required amount and will not need to be provided in another location on that rectangle side. Microsoft Windows NT 6.1.7601 Service Pack 1 a The interior side of all exterior walls shall be sheathed with minimum ½ -inch gypsum wallboard unless otherwise permitted to be excluded by this subsection. All edges of panel-type wall bracing, except horizontal joints in GB bracing, shall be attached to framing or blocking. Microsoft Windows NT 6.1.7601 Service Pack 1 b The actual measured wall height shall include stud height and thickness of top and bottom plates. The actual wall height shall be permitted to exceed the listed nominal values by not more than 4 ½ inches. Tabulated bracing amounts in s. SPS 321.25 (8) (c) are based on a 10-foot nominal wall height for all bracing methods and shall be permitted to be adjusted to other nominal wall heights not exceeding 12 feet in accordance with footnotes to Table 321.25–I or Table 321.25–J. Microsoft Windows NT 6.1.7601 Service Pack 1 c LIB is not permitted for walls supporting a roof and two floors. Two LIB braces installed at a 60 o angle from horizontal shall be permitted to be substituted for each 45 o angle LIB brace. Microsoft Windows NT 6.1.7601 Service Pack 1 d Bracing with CS-WSP and CS-SFB shall have sheathing installed on all sheathable surfaces above, below, and between wall openings. Microsoft Windows NT 6.1.7601 Service Pack 1 d Shall be attached to the top and bottom plates and any intermediate studs, in one continuous length. Microsoft Windows NT 6.1.7601 Service Pack 1 e Each braced panel may contain no more than one hole, having a maximum dimension of no more than ten percent of the least dimension of the panel, and confined to the middle three-fourths of the panel. - See PDF for table - See PDF for table Microsoft Windows NT 6.1.7601 Service Pack 1 a Sheathing shall extend from the top of the top plate to the bottom of the bottom plate and may be multiple sheets. All joints shall be blocked. Microsoft Windows NT 6.1.7601 Service Pack 1 b Interpolation is permitted. Microsoft Windows NT 6.1.7601 Service Pack 1 Figure 321.25–A Microsoft Windows NT 6.1.7601 Service Pack 1 METHOD PF – PORTAL FRAME BRACE CONSTRUCTION Microsoft Windows NT 6.1.7601 Service Pack 1 - See PDF for diagram Microsoft Windows NT 6.1.7601 Service Pack 1 Note: Steel headers are permitted if designed by structural analysis. Microsoft Windows NT 6.1.7601 Service Pack 1 Note: As shown in the above cross-section, 1/2-inch gypsum wallboard is not required on the interior side of the wall. Microsoft Windows NT 6.1.7601 Service Pack 1 FIGURE 321.25-B Microsoft Windows NT 6.1.7601 Service Pack 1 DEFINING BUILDING SIDES AND LENGTHS WITH ONE OR MORE
CIRCUMSCRIBED RECTANGLES a,b,c Microsoft Windows NT 6.1.7601 Service Pack 1 - See PDF for diagram Microsoft Windows NT 6.1.7601 Service Pack 1 (1) Basic floor plan Microsoft Windows NT 6.1.7601 Service Pack 1 - See PDF for diagram Microsoft Windows NT 6.1.7601 Service Pack 1 (2) Angled-building-side plan d Microsoft Windows NT 6.1.7601 Service Pack 1 - See PDF for diagram Microsoft Windows NT 6.1.7601 Service Pack 1 (3) Angled floor plan e Microsoft Windows NT 6.1.7601 Service Pack 1 a Each floor plan level shall be circumscribed with one or more rectangles around the entire floor plan at the floor level under consideration as shown. When multiple rectangles are used, each side shall be braced as though it were a separate building and the bracing amount added together along the common wall where adjacent rectangles overlap or abut. Microsoft Windows NT 6.1.7601 Service Pack 1 b Rectangles shall surround all enclosed plan offsets and projections. Chimneys, partial height projections, and open structures, such as carports and decks, shall be excluded from the rectangle. Microsoft Windows NT 6.1.7601 Service Pack 1 c Each rectangle shall have a maximum rectangle length-to-width ratio of 3:1. Microsoft Windows NT 6.1.7601 Service Pack 1 d Projected contributing lengths of angled braced wall panels shall be assigned to the closest rectangle sides, as shown for the angled corner in the angled-building-side-plan shown above. Microsoft Windows NT 6.1.7601 Service Pack 1 e Braced wall panels located on a common wall where angled rectangles intersect, as shown in Figure 321.25-B(3), shall have their contributing length applied towards the required length of bracing for the parallel rectangle side and its projected contributing lengths towards the adjacent angled rectangle sides. Where the common side of rectangle 2 as shown in Figure 321.25-B(3) has no physical wall, the portion shall be designed in accordance with s. SPS 321.25 (8) (a) . Microsoft Windows NT 6.1.7601 Service Pack 1 TABLE 321.25–I Microsoft Windows NT 6.1.7601 Service Pack 1 REQUIRED NUMBER OF INTERMITTENT BRACED WALL PANELS
ON WALLS PARALLEL TO EACH RECTANGLE SIDE
AT EACH FLOOR LEVEL a,b,c,d,e,f, h, j - See PDF for table Microsoft Windows NT 6.1.7601 Service Pack 1 a Interpolation is permitted. Extrapolation to buildings larger than addressed in this table is prohibited. Microsoft Windows NT 6.1.7601 Service Pack 1 b This table applies to wind exposure category B. For wind exposure category C or D, multiply the number of braced wall panels required by 1.3 or 1.6, respectively. Microsoft Windows NT 6.1.7601 Service Pack 1 Wind exposure category B is comprised of urban and suburban areas, wooded areas, or other terrain with numerous closely spaced obstructions having the size of single-family dwellings or larger. Exposure B shall be assumed unless the site meets the definition of another type exposure. Microsoft Windows NT 6.1.7601 Service Pack 1 Wind exposure category C is comprised of flat, open country and grasslands with scattered obstructions, including surface undulations or other irregularities, having heights generally less than 30 feet extending more than 1,500 feet from the building site in any quadrant. This exposure also applies to any building located within Exposure B type terrain where the building is directly adjacent to open areas of Exposure C type terrain in any quadrant for a distance of more than 600 feet. Microsoft Windows NT 6.1.7601 Service Pack 1 Wind exposure category D is comprised of flat, unobstructed areas exposed to wind flowing over open water for a distance of at least 1 mile. This exposure applies only to those buildings and other structures exposed to the wind coming from over the water. Exposure D extends inland from the shoreline a distance of 1,500 feet or 10 times the height of the building or structure, whichever is greater. Microsoft Windows NT 6.1.7601 Service Pack 1 c Tabulated values are based on a nominal wall height of 10 feet. For nominal wall heights other than 10 feet and not more than 12 feet, multiply the required number of brace panels by the following factors: 0.9 for 8 feet, 0.95 for 9 feet, 1.15 for 11 feet, or 1.3 for 12 feet. Microsoft Windows NT 6.1.7601 Service Pack 1 d Tabulated values are based on a roof with a top-of-wall-to-ridge height of 10 feet. For top-of-wall-to-ridge heights other than 10 feet, multiply the required number of brace panels by the following factors for each floor level support condition: Microsoft Windows NT 6.1.7601 Service Pack 1 Roof only – 0.7 for 5 feet, 1.3 for 15 feet, or 1.6 for 20 feet Microsoft Windows NT 6.1.7601 Service Pack 1 Roof + 1 Floor – 0.85 for 5 feet, 1.15 for 15 feet, or 1.3 for 20 feet Microsoft Windows NT 6.1.7601 Service Pack 1 Roof + 2 Floors – 0.9 for 5 feet or 1.1 for 15 feet. Microsoft Windows NT 6.1.7601 Service Pack 1 e Where minimum 1/2-inch gypsum wallboard is not included on the interior side of the wall, multiply the number of braced wall panels by 1.7 for LIB bracing or 1.4 for all other bracing methods, except this increase is not required for the portal frame method. Microsoft Windows NT 6.1.7601 Service Pack 1 f Adjustments in footnotes b to e apply cumulatively. Fractions of panels shall be rounded to the nearest one-half braced wall panel. Microsoft Windows NT 6.1.7601 Service Pack 1 g Perpendicular sides to the front and rear sides are the left and right sides. Perpendicular sides to the left and right sides are the front and rear sides. See Figure 321.25–B. Microsoft Windows NT 6.1.7601 Service Pack 1 h The following braced wall panel conditions shall be permitted to be counted as one-half a braced wall panel toward meeting the required number of panels: (1) one 60 degree LIB; (2) one 48" GB or one 96" GB with gypsum wallboard on one side; (3) one 36" WSP or SFB braced wall panel for wall heights not more than 9 feet; (4) a 48" WSP or SFB braced wall panel where there is no more than one unblocked horizontal joint; or (5) one PF brace panel complying with Figure 321.25–A. Microsoft Windows NT 6.1.7601 Service Pack 1 i This value of less than 2 serves only as the beginning value for calculation purposes. The resulting value shall be 2 or greater, to be consistent with subd. 2. Microsoft Windows NT 6.1.7601 Service Pack 1 j Any floor, habitable or otherwise, that is contained wholly within the roof rafters or roof trusses is exempt from being considered a floor for purposes of determining wall bracing if the top-of-wall-to-ridge height does not exceed 20 feet and if no opening in the roof exceeds 48 inches in height. Microsoft Windows NT 6.1.7601 Service Pack 1 Table 321.25–J Microsoft Windows NT 6.1.7601 Service Pack 1 REQUIRED LENGTH OF CONTINUOUS BRACING ON WALLS PARALLEL TO EACH RECTANGLE SIDE AT EACH FLOOR LEVEL a,b,c,d,e,g,h, j - See PDF for table Microsoft Windows NT 6.1.7601 Service Pack 1 a Interpolation is permitted. Extrapolation to buildings larger than addressed in this table is prohibited. Microsoft Windows NT 6.1.7601 Service Pack 1 b This table applies to wind exposure category B. For wind exposure category C or D, multiply the required length of wall bracing by 1.3 or 1.6, respectively. Wind exposure categories are as defined in Table 321.25–I footnote b. Microsoft Windows NT 6.1.7601 Service Pack 1 c Tabulated values are based on a nominal wall height of 10 feet. For nominal wall heights other than 10 feet, multiply the required length of bracing by the following factors: 0.90 for 8 feet, 0.95 for 9 feet, 1.05 for 11 feet, or 1.10 for 12 feet. Microsoft Windows NT 6.1.7601 Service Pack 1 d Where minimum ½ -inch gypsum wallboard interior finish is not provided, the required bracing amount for the affected rectangle side shall be multiplied by 1.4, except this increase is not required for the portal frame method. Microsoft Windows NT 6.1.7601 Service Pack 1 e Adjustments in footnotes b to d apply cumulatively. Microsoft Windows NT 6.1.7601 Service Pack 1 f Perpendicular sides to the front and rear sides are the left and right sides. Perpendicular sides to the left and right sides are the front and rear sides. See Figure 321.25–B. Microsoft Windows NT 6.1.7601 Service Pack 1 g Continuous sheathing shall be applied to all surfaces of the wall, including areas between brace panels and above and below wall openings. Microsoft Windows NT 6.1.7601 Service Pack 1 h When used on a wall line with continuous sheathing, each portal frame panel is counted for its actual length in contributing toward the length of continuous sheathing used on other portions of the same wall line, such as the building side at a given story level. Microsoft Windows NT 6.1.7601 Service Pack 1 i Any value of less than 4.0 in this table serves only as the beginning value for calculation purposes. The resulting value shall be 4.0 or greater, to be consistent with Table 321.25–H and subd. 2. Microsoft Windows NT 6.1.7601 Service Pack 1 j Any floor, habitable or otherwise, that is contained wholly within the roof rafters or roof trusses is exempt from being considered a floor for purposes of determining wall bracing if the top-of-wall-to-ridge height does not exceed 20 feet and if no opening in the roof exceeds 48 inches in height. Microsoft Windows NT 6.1.7601 Service Pack 1 Figure 321.25–C Microsoft Windows NT 6.1.7601 Service Pack 1 LOCATION OF BRACED WALL PANELS ALONG A BUILDING SIDE a Microsoft Windows NT 6.1.7601 Service Pack 1 - See PDF for diagram Microsoft Windows NT 6.1.7601 Service Pack 1