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Questions and Answers about Wisconsin's Uniform Dwelling Code See SPS 320-325, Uniform Dwelling Code, onlineHow are campgrounds in Wisconsin affected by the UDC? Is there a product evaluation for Form-a-Drain Footing Form and Foundation Drainage System? Yes, see PDF file. Is there additional information about acceptable designs for increased sill plate overhang? Yes, see PDF file. (April 7, 2010) SPS 320.09(4)(b) Foundation systems serving manufactured homes may be designed by structural analysis but do not need to be signed and sealed by a registered professional. Here is a PDF file concerning an acceptable slab on grade foundation system for manufactured homes. ---------- ----------- SPS 3 21.02(1)(c) Dwellings shall be designed and constructed to withstand a horizontal and uplift pressure of 20 pounds per square foot acting over the surface area. Question: When designing the braced wall lines to comply with SPS 3 21.25(8)(1), may I use the ASCE 7 standard as an option to determine wind loads on a dwelling even though the resultant wind pressure may be less than 20 PSF? Answer (July 15, 2011): Yes. ASCE 7 is considered an accepted engineering practice. Conditions of acceptance are: that version 2005 is used, that a minimum wind speed of 90 MPH (3-second gust) be used, that the appropriate exposure factor be used, and that it be applied to the whole dwelling for determining wall bracing. The ASCE 7 standard may also be used to determine the wind pressure on tall walls only if the ASCE 7 design standard is also being used for determining the wall bracing requirements of the dwelling. This design methodology may also be used to determine wall bracing needs for an addition, and only the addition, to an existing dwelling as long as it is applied to the complete addition. --------------------- SPS 3 21.02(1)(d) Question: Is there an Alternate Fastening Schedule for Braced Wall Panels? Answer (April 7, 2010): Yes, see PDF file. ---------- SPS 3 21.08(1) Question: Is there additional information on fire separation and living unit separation? Answer (April 7, 2010): Yes, see PDF file. ---------- SPS 3 21.25(8)(d), Table 21.25-H Braced wall panels shall begin no more than 12.5 feet from each end of a braced wall line per figures 321.25−A and 321.25−B, and shall be located every 25 feet on center. Bracing amounts shall comply with Table 321.25−H for the bracing materials and methods specified under par. (b). Question: Every time I have a braced wall line do I have to perform the percentage calculations to determine if the total length of the braced wall panels provided meet Table 321.25-H? Answer: The builder must provide the minimum length of braced wall panel in the braced wall line required by this section. To simplify the process of determining the required length of braced panel required using the intermittent method of wall bracing under SPS 321.25(8) the department has developed a table, “Minimum Bracing Length for Walls”. This table has various braced wall line lengths and resultant required braced wall panel length based on percentages specified in Table 321.25-H. For example, if I have a braced wall line in a wall of up to 10 feet tall supporting a floor and roof and the bracing method used is gypsum wall board you would use the column with the 25% value. ----------- SPS 3 21.25(9)5., Fig. 321.25-K, and Table 321.25-L For purposes of resisting wind pressures acting perpendicular to the wall, the minimum requirements of Figure 321.25-K are sufficient for wind speeds less than 110 mph in exposure category B. For exposure categories C and D, the header to jack stud strap requirements and the number of additional jack studs shall be in accordance with Table 321.25-L. Question: I already have a 2 X member used to support the door track on the inside face of the garage door. Can I use the wood member to support the lateral loads in place of the 1,000 lb. metal strap required by this section? Answer (July 15, 2011): Yes. To replace a 1,000 lb. strap the 2x4 must be attached with fourteen 10d common nails (0.148 x 3 inches). Seven nails should be placed in the header region and seven placed in the wall segment. ---------- SPS 3 22.21(2)(a) Wind Wash Protection. Except as provided under SPS 322.39(4) for cathedral ceilings, all air−permeable insulation materials installed in any position other than horizontal, shall be covered on the cold−in−winter side with wind wash protection consisting of a permanently attached material of low air permeability. AND SPS 3 22.39(4) CATHEDRAL CEILINGS. Air-permeable insulation in a cathedral ceiling assembly shall fill the entire cavity space unless an air barrier separates the top of the insulation from the ventilation space. Question: If I have a sloped ceiling that is not a cathedral ceiling, such as that created by scissor trusses,that is insulated with an air-permeable insulation material, e.g. fiberglass and cellulose,do I need the wind wash protection required by this section? Answer (July 15, 2011): No, if the ceiling is sloped less than 60 degrees from the horizontal and it is not a cathedral ceiling, wind wash protection is not required. A cathedral ceiling is a sloped ceiling, with closely-spaced, parallel ceiling and roof finishes. Discussion. ---------- SPS 3 22.38(1)(d) The vapor retarder shall be continuous. All joints in a vapor retarder consisting of sheet material shall be overlapped 6 inches and taped or sealed. Rips, punctures and voids in the vapor retarder shall be patched with vapor retarder materials and taped or sealed. Question: If I overlap the vapor retarder at least 6 inches at a stud or ceiling rafter/truss and have drywall or other rigid material permanently fastened to the stud or rafter/truss do I still need to tape or caulk/seal the vapor retarder’s lapped joint? Answer (July 15, 2011): No. The fasteners in the drywall or other rigid material provide the sealing required by this code section. This is no different when SPS 322.38(2)(c)3 of the code only requires the nailing tabs of foil or Kraft paper be tightly fastened to the face of the framing members. ---------- SPS 3 2.38(3)(d) - Edges of the vapor retarder shall extend up the edges of the slab at least to the top of the slab. Question: Do I need to extend my vapor retarder up the edges to the top of the floor slab in every case? Answer (Dec. 1, 2009): No. The vapor retarder shall be provided beneath the entire concrete floor slab, but need not extend up the edge to the top of the slab provided the floor slab is cast over a code-complying footing and is tight against the wall the footing is supporting or, if it is not poured over the footing, is cast tight against the concrete footing itself. A concern has been expressed that the code requirement placing the vapor retarder between the edge of the slab and the wall or footing could create an open joint that could be a route for bulk moisture to migrate from the sub-grade into the building interior. The foundation which the floor slab extends over, or is cast against, provides an equivalent degree of protection from the propagation of moisture in the soil beneath the foundation that a vapor retarder alone would provide. Note: This Q&A is for a concrete floor slab cast against concrete walls or footings. Concrete floor slabs cast against wood foundations shall have a vapor retarder installed in accordance with the adopted installation standard ANSI/AF&PA PWF specified in Table 321.24-2. ---------------- SPS 3 22.39(4) CATHEDRAL CEILINGS. Air-permeable insulation in a cathedral ceiling assembly shall fill the entire cavity space unless an air barrier separates the top of the insulation from the ventilation space. AND SPS 3 22.21(2)(a) Wind Wash Protection. Except as provided under SPS 322.39 (4) for cathedral ceilings, all air−permeable insulation materials installed in any position other than horizontal, shall be covered on the cold−in−winter side with wind wash protection consisting of a permanently attached material of low air permeability. Question: If I have a sloped ceiling that is not a cathedral ceiling, such as that created by scissor trusses, that is insulated with an air-permeable insulation material, e.g. fiberglass and cellulose,do I need the wind wash protection required by this section? Answer (July 15, 2011): No, if the ceiling is sloped less than 60 degrees from the horizontal and it is not a cathedral ceiling, wind wash protection is not required. A cathedral ceiling is a sloped ceiling, with closely-spaced, parallel ceiling and roof finishes. Discussion. 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