eLaws | eCases | Wisconsin Courts | Counties & Cities of Wisconsin | Code of Federal Regulations | United States Code |
 West Allis
 Code of Ordinances
 Municipal Code
 Chapter 13. Building Code

  Wood Frame Construction.  

Latest version.
  • (1) 
    Grades of Lumber. All structural members including columns, girders, joists, studding and rafters shall be No. 1 Common or better according to American Lumber Standards.
    (2) 
    Exterior Walls and Wall Covering.
    (a) 
    Exterior walls of one and two (2) story frame buildings shall be constructed with studding not less than two (2) inches by four (4) inches spaced sixteen (16) inches on centers, except frame garages, which may have studding as hereinafter ordained.
    Buildings three (3) stories in height shall have the first story studs not less than two (2) inches by six (6) inches spaced sixteen (16) inches on centers.
    Where studs continue through more than one story, joists shall be nailed securely to the studs and shall be supported upon a one (1) inch by four (4) inch ribbon notched into the studs and securely nailed thereto. Where stories are framed separately, each tier of studding shall have top and bottom plates and top plates shall be doubled and lapped at all corners and intersections. Laps in separate pieces of the top plate shall be staggered thirty-two (32) inches.
    (b) 
    All frame buildings shall have exterior walls covered with solid wood sheathing not less than thirteen-sixteenths (13/16) of an inch thick or with such other sheathing material as is approved by the Inspector.
    Wood sheathing shall be securely nailed with at least two (2) 8d common nails in every board on each stud when six (6) inch sheathing is used and with three (3) such nails if eight (8) inch boards are used.
    Wood sheathing shall be covered on the outside with waterproof building paper.
    When approved sheathing other than wood is used, the framing of the building shall be thoroughly braced in all outside walls and as may be required in cross partitions in each story. If such sheathing is not waterproof, it shall be covered with waterproof building paper.
    (c) 
    Bearing headers over openings in exterior bearing walls and interior bearing partitions shall conform with the following table:
    Size of Bearing Headers
    Maximum Allowable Span
    2-2" x 4" on edge
    4'
    2-2" x 6" on edge
    5'6"
    2-2" x 8" on edge
    7'6"
    2-2" x 10" on edge
    9'
    2-2" x 12" on edge
    11'
    All openings four (4) feet wide or less shall be provided with double headers of not less than two (2) inches by four (4) inches placed on edge. All openings more than four (4) feet wide shall be trussed or provided with headers which shall have not less than two (2) inch solid bearing to the floor or bottom plate.
    (d) 
    Where studs pass through from floor to floor, they shall be provided with suitable fire stops at the point of passage through the floor joists. If cove ceilings are used, the fire stops shall be placed at the bottom of the cove. Studs around stairwell openings shall be fire stopped at each story. Fire stops shall be tightly fitted between studs and shall not be less than (two) inches in thickness and be the same width as the studding.
    (3) 
    Stairways. Every stairway except attic stairs shall have a uniform rise of not more than seven and one-half (7-1/2) inches, and a uniform tread of not less than nine (9) inches measuring from tread to tread and from riser to riser. There shall be no more than eighteen (18) risers in any run.
    (4) 
    Interior Partitions. All interior bearing and nonbearing partitions shall be constructed, framed and fire stopped as specified for exterior walls, except that interior nonbearing partitions may have a single top plate.
    (5) 
    Floor Construction. All one and two (2) family residence buildings shall be designed to support a superimposed live load on each floor, except attic, of not less than forty (40) pounds per square foot of horizontal area.
    (a) 
    Girders. Girders supporting first floor joists in residence buildings shall conform to the following table:
    Wood girders based on allowable stresses for No. 1 Common Pine or Douglas Fir.
    Width of Floor Tributary to Beam
    Span of Beam (Center to Center of Bearings)
    No. of Floors and Ceilings
    Size of Wood Beam
    Size of Steel I Beams
    18 ft.
    7 ft.
    1
    6 x 8
    5 in. - 10.0 lbs.
    18 ft.
    8 ft.
    1
    8 x 8
    6 in. - 12.5 lbs.
    12 ft.
    9 ft.
    1
    6 x 8
    6 in. - 12.5 lbs.
    12 ft.
    10 ft.
    1
    8 x 8
    7 in. - 15.3 lbs.
    18 ft.
    10 ft.
    1
    8 x 10
    7 in. - 15.3 lbs.
    14 ft.
    7 ft.
    2
    8 x 8
    6 in. - 12.5 lbs.
    18 ft.
    7 ft.
    2
    8 x 10
    7 in. - 15.3 lbs.
    12 ft.
    8 ft.
    2
    8 x 8
    6 in. - 12.5 lbs.
    18 ft.
    8 ft.
    2
    8 x 10
    7 in. - 15.3 lbs.
    14 ft.
    9 ft.
    2
    8 x 10
    7 in. - 15.3 lbs.
    18 ft.
    9 ft.
    2
    8 x 12
    8 in. - 18.4 lbs.
    16 ft.
    10 ft.
    2
    8 x 12
    8 in. - 18.4 lbs.
    (b) 
    Moisture Conditions. When columns or posts supporting girders or first floor joists are exposed to moisture, such as on the ground or basement floor, the foundation or bearing shall be of concrete or masonry material and shall be built up at least six (6) inches above the basement floor level.
    (c) 
    Floor Joists. Floor joists in residences shall conform to the following table:
    Table "A" No. 1 Common Hemlock, Norway Pine or Spruce.
    Table "B" No. 1 Common Yellow Pine or Douglas Fir.
    Size of Joists
    Spacing of Joists
    Maximum Allowable Span
    (Feet and Inches)
    Center to Center
    (in inches)
    Table A
    Table B
    2 x 8
    12
    11-7
    13-4
    16
    10-1
    11-8
    2 x 10
    12
    14-7
    16-10
    16
    12-8
    14-8
    2 x 12
    12
    17-6
    20-2
    16
    15-3
    17-8
    2 x 14
    12
    20-4
    23-6
    16
    17-10
    20-7
    Floor joists shall not be less than two (2) inches by eight (8) inches, except that two (2) inches by six (6) inches joists may be used in attics where no attic floor is installed.
    Wooden floor joists installed in buildings without a basement shall have a clear space of at least twelve (12) inches between the bottom of the joists and surface of the ground underneath. Vents shall be placed at opposite ends of all such under-floor spaces. Such floors shall be effectively insulated as provided for in Sec. 13.08(1)(g).
    (6) 
    Backing for Lath. When backing for lath is necessary, such backing shall not be less than one (1) inch by four (4) inches nailed solidly to the stud or joist.
    (7) 
    Roof and Ceiling Construction. The following table gives maximum allowable span for ceiling and joists:
    Table "A" No. 1 Common Hemlock, Norway Pine or Spruce.
    Table "B" No. 1 Common Yellow Pine or Douglas Fir.
    Size of Joists
    Spacing of Joists
    Center to Center
    (inches)
    Maximum for Ceilings Joists No Floor Load Above
    Maximum for Flat Roof Joists
    Table A
    Table B
    Table A
    Table B
    2 x 6
    12
    13-0
    15-0
    10-4
    12-0
    16
    11-0
    13-0
    9-1
    10-6
    24
    7-5
    8-72
    2 x 8
    12
    17-0
    19-0
    13-9
    15-11
    16
    15-0
    17-0
    12-0
    13-11
    24
    9-11
    11-5
    2 x 10
    12
    21-0
    23-0
    17-3
    19-11
    16
    19-0
    21-0
    15-1
    17-4
    24
    12-6
    14-5
    (8) 
    Frame Roofs.
    (a) 
    In General. Roofs shall be designed to support a superimposed live load of thirty (30) pounds per square foot.
    (b) 
    Pitched Roofs. Two (2) inch by four (4) inch material may be used for rafters when the pitch is one-third (1/3) or more, span not over twelve (12) feet and the spacing not more than sixteen (16) inches center to center.
    (c) 
    Flat Roofs. Minimum size for joist on flat roofs shall be two (2) inches by six (6) inches.
    (d) 
    Roof Covering. Wherever a composition roofing is used, the roof construction shall be solidly sheathed.
    (e) 
    Ordinary Roofing. "Ordinary" roof coverings shall be any roof covering which meets the requirements specified for the Class C specifications of the Underwriters.
    (f) 
    Wood Shingles. Wood shingles used as roof covering shall be of clear vertical grain all-heart wood and shall be not less than five (5) shingles to two (2) inches in thickness at the butt (U.S. Government Standard). All wood shingles shall be nailed firmly with copper, zinc, zinc-coated, galvanized or commercially pure from nails of at least twelve and one-half (12-1/2) gauge and not less than one and one-quarter (1-1/4) inches long. Each shingle shall be nailed with at least two (2) nails driven substantially into the supporting roof construction. All wood shingles shall be laid with the following exposures as compared to total length of shingle:
    Total Length of Shingle
    Permissible Exposed Length
    16 inches
    4 1/2 inches
    18 inches
    5 1/2 inches
    24 inches
    7 1/2 inches
    (9) 
    Combustible Insulating Materials. Combustible insulating materials may be placed in partitions, floor or roof framing, but shall in no way interfere with or form a part of the fire blocking or fire separations required by this Code.
    (10) 
    Drainage of Roof. Except for private accessory buildings, all roofs of all buildings and structures hereafter erected and all roofs of all existing buildings and structures shall be provided with approved water-tight gutters and conductors for conducting water from roofs onto splash blocks or into street gutters in such a manner as to prevent basement leakage of the home on which the gutters and conductors are attached, or to adjoining homes and so as to prevent the erosion of soil or other similar damage to adjoining properties. Such gutters shall be of a size approved and designated by the Building Inspector, but not to exceed four (4) inches. Such gutters and conductors shall be fastened to place in an approved manner and shall be maintained in good repair at all times.