A. General:
1. Ice Barrier: All roofs shall have an ice barrier that consists of at least 2 layers of asphalt saturated underlayment, a minimum of 30 pounds per 100 square feet cemented together, a self- adhering polymer modified bitumen sheet or equivalent. The ice barrier shall extend from the eave edge to a point a minimum of 24" inside the interior wall line.
2. Roof Slope:
a. Tile roof (except porches): 5 in 12 minimum.
b. Tile roof of porch or attached garage: 3 in 12 minimum.
c. Built up roofs (gravel or slag surface): 3 in 12 minimum.
d. Built up roof with mineral surface cap sheet may be flat.
e. When materials and method of application provide precautions in excess of these 4 minimum requirements to assure a weather tight roof, above roof slopes may be reduced, subject to the acceptance by building officer.
3. Double Starting Row: Double starting row on all shingle applications.
4. Nails For Attaching Roof Covering: Copper, hot dipped, galvanized nails, or, aluminum nails.
B. Asphalt Shingles:
1. Fire underwriters class C label on each bundle.
2. Asphalt shingles may be used as follows: Shingles of not less than 235 pounds weight per square may be laid on slopes of not less than 2 in 12 pitch, provided that underlayment is not less than 2 layers of 15 pound saturated felt applied to the deck with a 19" lap. Started course of 12", 15 pound felt shall be covered with asphalt cement, and each succeeding course which lies from the eaves to a point on the roof 24" inside the inside wall line of the building. Underlayment to be secured to deck by either 3/4" staples or 3/4" roofing nails, using only enough fasteners to hold the material in place until the shingles are applied. Tabs shall be less than 3 in 12 pitch, cementing not required, and single underlayment of 15 pound saturated felt permitted.
3. Asphalt shingles of not less than 235 pounds weight per square may be laid at not less than 3 in 12 pitch, minimum 2" head lap, with single underlayment. Dutch lap method will require clips.
4. Reroofing (no more than 2 layers) without architect's written approval.
C. Wood Shingles:
1. Edge grain: Tapered shingles (no. 1 grade).
2. Minimum size:
Length: 16"; thickness: 5 butts in 2"
Length: 18"; thickness: 5 butts in 21/4"
Length: 24"; thickness: 4 butts in 2"
3. Maximum exposure:
Slope Of Roof | Exposure For Shingle Length (Inches) | |||
Rise | Run | 16 | 18 | 24 |
3 to 7 | 12 | 4 | 41/2 | 6 |
7 to 18 | 12 | 5 | 51/2 | 71/2 |
4. Underlay not permitted.
D. Asbestos-Cement Shingles:
1. Quality: Dense, hard structure, and thoroughly seasoned (see section 8-3-24, appendix A, of this chapter).
2. Fire underwriters' class A and B label on each bundle.
3. Underlay: 1 layer asphalt saturated felt, approximately 30 pounds per 100 square feet.
4. American method:
Standard shingle:
Minimum weight per square: 470 pounds.
Length: 16" inches; maximum exposure: 7".
Length: 15"; maximum exposure: 61/2".
Length: 12"; maximum exposure: 5".
Strip shingle:
Minimum weight per square: 250 pounds.
5. Dutch method:
Minimum weight per square: 265 pounds.
Minimum head lap: 3".
Minimum side lap: 4".
6. French or hexagonal method:
Minimum weight per square: 25 pounds.
Minimum overlap: 2 edges, 3.
7. Minimum pitch: 5 in 12.
E. Tile Roofing:
1. Quality: Hard burned roofing tile.
2. Underlay: 1 layer asphalt saturated felt, approximately 30 pounds per 100 square feet.
3. Shingle tile, American method:
Length: 16"; maximum exposure: 7".
Length: 15"; maximum exposure: 61/2".
Length: 14"; maximum exposure: 6".
Length: 12"; maximum exposure: 5".
4. Interlocking tile and curved tile: Lay in accordance with manufacturer's recommendations.
F. Slate Shingles:
1. Quality: Free from knots or knurls and of reasonably smooth cleavage. (See section 8-3-24, appendix A, of this chapter.)
2. Underlay: Asphalt saturated felt approximately 30 pounds per 100 square feet.
3. Laid American method:
Minimum thickness: 3/16".
Length: 18"; maximum exposure: 71/2".
Length: 16"; maximum exposure: 61/2".
Length: 14"; maximum exposure: 51/2".
Length: 12"; maximum exposure: 41/2".
Length: 10"; maximum exposure: 31/2".
4. Minimum pitch: 5 in 12.
G. Built Up Roofs:
1. Asphalt or tar and gravel coverings, including flashings: Comply with requirements of Underwriters Laboratories, Inc. Built up roof coverings: Minimum 3-ply.
2. Apply according to manufacturer's directions.
3. Each ply of felt: Minimum weight: 15 pounds per 100 square foot.
4. Surface with roofing gravel or crushed stone, approximately 400 pounds per 100 square feet; or crushed slab, approximately 300 pounds per 100 square feet.
5. Top ply of felt and crushed stone or slab surfacing may be replaced with 1 layer of mineral surfaced cap sheet, minimum weight: 85 pounds per square.
6. Asbestos felt built up roofs may be smooth surface, if applied according to manufacturer's directions.
H. Metal Roofs:
1. Materials: (See section 8-3-24, appendix A, of this chapter.) Galvanized sheet metal: 26-gauge sheets, 1.25 ounce (total weight both sides) zinc coating per square foot. Copper: 16 ounce soft (roofing temper). Roofing tin: 40 pound coating. Lead: sheet lead, 21/2" pounds per square foot.
2. Nails: Hard copper or copper alloy, for copper roofs. Hot dipped, galvanized, for galvanized sheet metal roofs.
3. Seams: Flat or standing. Flat seams; locked and soldered.
I. Roof Coverings: Roof coverings such as aluminum, metal shingles, canvas or roll roofing, may be used when the type and weight of material, and method of application are acceptable to the building officer. (Ord. 2008-09-01, 9-24-2008)