(a) Wooden roof rafters shall not be less than standard two inches in thickness and shall be framed around each chimney with a clearance of not less than two inches between the chimney and framing. They shall be not more than eighteen inches on centers and of the following size for pitched roofs:
Span | Size in inches |
12 ft. or less | 2 x 6 |
12 ft. to 20 ft. | 2 x 6 |
Over 20 ft. | 2 x 8 |
(b) All flat-roof rafters over six feet span shall be not less than two inches by six inches and spaced not more than sixteen inches on centers. All bearers or ribbon boards shall be not less than one inch by six inches.
(c) The ends of all wooden floor joists and beams, which rest on stone, cement-concrete or concrete block walls in all buildings other than dwellings, shall be cut to a bevel of three-quarters of an inch for each three inches in depth, but need not exceed a total of three inches.
(d) Where wood studding is used around stairways in multiple dwellings, public buildings and educational buildings, plastering shall be applied on metal lath affixed to both sides of such studding.
Exception: In two-story buildings containing a store on the first floor and one or two apartments on the second floor, the ceiling of the store may be of wood joists with metal lath and plaster ceiling or other fire resistant material. Wood studding may be used in partitions of the first story of these buildings, but metal lath or other fire-resistant material must be used on both sides of the same. The soffits of stairs leading to the apartments above the store shall be likewise covered. Wood furring may be used on walls of the first story if covered with a fire-resistant material. All attic spaces and all ventilating spaces under flat roofs must be provided with an opening suitable for entrance for inspection or repair purposes.
(e) Where wood lath is used, it must be spaced not less than one-half inch apart on the outside and not less than three-eighths of an inch on the inside, lathing to be broken every ten laths, with four-penny galvanized nails to be used on the outside and three-penny fine nails on the inside, and all outside corners to be reinforced with galvanized wire. All stucco covered structures shall be sheathed and lined with an approved building paper and counter lathed on not over sixteen-inch centers.
(f) Expanded metal lath for stud walls shall weigh not less than 2.5 pounds per square yard, and for ceilings shall weigh not less than 3.4 pounds per square yard. Flat ribbed metal lath shall weigh not less than 2.75 pounds per square yard, and for exterior stucco, expanded metal lath shall weigh not less than 3.4 pounds per square yard. All expanded metal lath used as a base for interior plaster shall be either painted or galvanized.
(g) Woven galvanized wire lath shall be number nineteen gauge wire with a weight of not less than 3.2 pounds per square yard.
(h) Paper backed galvanized wire lath shall have a maximum wire spacing of two inches between centers, for interior plastering shall weigh not less than 2.3 pounds per square yard and for exterior stucco shall weigh no less than 3.1 pounds per square yard. All metal lath used as base for exterior stucco shall be cut from zinc-coated sheet metal or fabricated from zinc-coated wire.
(i) All external angle corners for interior plaster work shall have galvanized iron corner beads, and all intersections of walls at corners and at ceilings shall be lathed with metal lath corner strips not less than three inches on each surface.
(j) When metal lath is used as a base for stucco, the lath shall be held at least three-eighths of an inch away from the sheathing by use of furring nails, wood furring strips or self-furring lath.
(k) When metal lath, except paper backed metal lath, is applied to solid wood surfaces such as wood beams, lintels, girders, siding, etc., the surface shall be covered with water-proofed paper before the metal lath is applied. Furring nails or strips shall be provided for fastening on metal lath.
(l) All interior plaster when applied to a lath base shall be three-coated work and shall have a minimum thickness of one-half inch over the lath base. The scratch or first coat may be omitted when plaster is applied directly to masonry or rock lath or similar material. Plaster shall be mixed and applied exactly according to manufacturer's directions. Lump lime, when used for plastering, shall be thoroughly slacked. The lime puddy shall then be screened and allowed to stand in a metal tank or other suitable receptable, at least a week before being used. If hydrated lime or patent plasters are used, they shall be mixed and applied according to manufacturer's directions.
(m) Stucco shall have a base of Portland cement or other approved material, and the metal lath shall be entirely embedded in the stucco. First and second coats shall be composed of one part Portland cement, three parts sand, and hydrated lime equal to ten percent of the cement. The first coat shall be applied to a minimum thickness and scratched, kept damp for at least three days and then allowed to dry. After the scratch coat is dry, the surface shall be moistened thoroughly and evenly and immediately receive the second coat to at least one-half inch thickness and straight and true in every direction. This second coat shall be kept damp for at least three days and then allowed to dry thoroughly. A third coat shall be applied and treated in a like manner. No exterior stucco work shall be applied to wood lath, and at no time will exterior stucco work be allowed to proceed when the temperature is less than forty degrees F.
(n) All roof covers of tile, slate, asbestos cement, or asphalt shingles shall be installed according to the manufacturer's directions, and roof sheathing shall be covered with saturated asphalt roofing felt of the following weights:
(1) Not less than thirty-pound felt under tile asbestos-cement shingle or slate roofs.
(2) Not less than thirty-pound felt under asphalt shingles where less than double thickness occurs at any point.
(3) Not less than fifteen-pound felt under asphalt shingles where double thickness is obtained at all points.
(4) No felt will be required where triple thickness asphalt shingles are obtained at all points, nor under wood shingles.
(o) The minimum pitch for asphalt shingle roof shall be five inches in twelve inches. A double starting row shall be attached on shingle installations.
(p) When slate is installed, exposure shall not exceed the following:
Fourteen-inch slate not over five and one-half inches to the weather
Sixteen-inch slate not over six and one-half inches to the weather
Eighteen-inch slate not over seven and one-half inches to the weather
(q) All other type shingles and tile shall be applied with exposures as recommended by the manufacturers.
(r) Asphalt or coal-tar pitch and gravel covering for flat roofs shall be at least four-ply, applied according to manufacturer's directions.
(s) Wood shingles shall be edge-grain tapered shingles, minimum thickness, five butts in two inches, and a double starting row used on all installations. Wood shingles exposure to the weather shall not exceed the following:
Maximum Wood-Shingle Exposures | ||||||||
Roof shingle exposure (in inches) | ||||||||
Side wall shingle exposures (in inches) | ||||||||
Roof shingle exposure (in inches) | ||||||||
Pitch of roof | Shingle length (in inches) | Thickness of courses | Shingle length (in inches) | |||||
Rise | Run | 16 | 18 | 24 | 16 | 18 | 24 | |
Maximum Wood-Shingle Exposures | ||||||||
Roof shingle exposure (in inches) | ||||||||
Side wall shingle exposures (in inches) | ||||||||
Roof shingle exposure (in inches) | ||||||||
Pitch of roof | Shingle length (in inches) | Thickness of courses | Shingle length (in inches) | |||||
Rise | Run | 16 | 18 | 24 | 16 | 18 | 24 | |
4 to 7 | 12 | 33/4 | 4½ | 53/4 | Single | 7% | 8% | 11 |
7 to 18 | 12 | 5 | 5½ | 7 | Double | 12 | 14 | 16 |
(t) Wood shingles on roofs with pitch of less than five inches to twelve inches shall be used on open porches only.
(u) All built-in flashing and counter-flashing overhead of openings, around chimneys, at intersections of roofs and walls, valleys, hips, ridges, and at horizontal and vertical intersections of stucco with other material, shall be of corrosion-resisting metal. All such metal other than copper, lead and zinc shall be painted on both sides before installation. For valleys in connection with asphalt shingle roofs, two thicknesses of mineral surface roll-roofing material cut from rolls weighing not less than eighty-five pounds per square may be used, provided such strips are not less than eighteen inches in width.
(Ord. 288. Passed 5-24-54.)