Exam Cheat Sheet · Quick Reference
ICC G15 Shingle Roofing Exam (2018 IBC/IRC)
National · Pearson Vue
National State Portion 60 questions
Key Distinctions
Per IBC 1507.9.5 and Table 1507.8, wood shakes require interlayment complying with ASTM D226, Type I, while Table 1507.8 lists 'No requirements' for interlayment under wood shingles (two fasteners per unit, solid sheathing in icing areas and bundle labeling apply to both).
IBC 2018 Pages 352 to 353IRC R905.8.6 requires 3/8 inch to 5/8 inch between wood shakes in the same course including tapersawn shakes, while IRC R905.7.5 sets 1/4 inch to 3/8 inch for wood shingles. (Under IBC 1507.9.8 the 3/8-to-5/8-inch spacing covers shakes and taper sawn shakes of naturally durable wood only; preservative-treated taper sawn shakes are 1/4 to 3/8 inch.)
IRC 2018 Page 440IBC 1507.9.8 requires 3/8 to 5/8 inch spacing between shakes in the same course for shakes and taper sawn shakes of naturally durable wood, but 1/4 to 3/8 inch only for preservative-treated taper sawn shakes.
IBC 2018 Page 353Asphalt shingle nails are minimum 12 gage [0.105 inch] shank with minimum 3/8-inch-diameter head complying with ASTM F1667, while tile nails are corrosion resistant, not less than 11 gage with a 7/16-inch head.
IRC Section R905.2.5Shank shall be not less than 0.083 inch for ring shank cap nails and not less than 0.091 inch for smooth shank cap nails (IRC R905.1.1 Exception 3.4; IBC 1507.1.1 Exception 3 / Table 1507.1.1(3) for V ≥ 140 mph).
IRC 2018 Page 436Clay/concrete tile valley flashing requires a rib not less than 1 inch high at the flow line (IBC 1507.3.9; IRC R905.3.8), while metal roof shingle valley flashing requires a rib not less than 3/4 inch high (IBC 1507.5.7; IRC R905.4.6).
IBC 2018 Section 1507.3.9ASTM D7158 is the primary required wind-resistance test for asphalt shingles with packaging labeled to the resulting classification, while ASTM D3161 is used under the exception only for shingles not within the scope of D7158 (and is the wind test for photovoltaic shingles per IRC R905.16.6).
IBC 2018 Page 342ASTM D3462 is the asphalt shingle product (material) standard required by IBC 1507.2.4 and IRC R905.2.4, whereas D7158 and D3161 are the wind-resistance test standards.
IBC 2018 Section 1507.2.4 (Asphalt shingles)IBC permits above-deck insulation covered with an approved roof covering where it passes NFPA 276 or UL 1256 tested as an assembly, while IRC permits it where covered with an approved roof covering and complying with FM 4450 or UL 1256.
IBC 2018 Page 356Base flashing against a vertical sidewall has code-prescribed minimum dimensions (4 inches high by 4 inches wide), while flashing against a vertical front wall, soil stack, vent pipe and chimney is applied in accordance with the asphalt shingle manufacturer's printed instructions.
IRC 2018 Sections R905.2.8.3 and R905.2.8.4Wood shingle valley flashing extends 10 inches from the centerline each way for slopes less than 12:12 and 7 inches each way at 12:12 and greater, while wood shake valley flashing (No. 26 gage minimum) extends not less than 11 inches from the centerline each way; metal roof shingle valleys extend 8 inches.
IRC 2018 Section R905.7.6Per IBC 1511.5, existing slate, clay or cement tile may be reinstalled if not damaged, cracked or broken and existing vent flashing, metal edgings, drain outlets, collars and metal counterflashings may be reinstalled unless rusted, damaged or deteriorated, but aggregate surfacing materials shall not be reinstalled under any condition.
IBC 2018 Section 1511.5The building official is appointed by the chief appointing authority of the jurisdiction, while the building official appoints deputy building officials, technical officers, inspectors, plan examiners and other employees with the concurrence of the appointing authority.
IBC 2018 Section 103.3 (with Section 103.2)Key Terms
Formulas to Know
Use the minimum number of fasteners required by the manufacturer, but not fewer than 4 fasteners per strip shingle or 2 fasteners per individual shingle; where the manufacturer specifies fewer (e.g., 3 per strip on a 6:12 roof), the code floor of 4 governs. Where roof slope exceeds 21:12, install as required by the manufacturer.Lower edge of each 18-inch-wide No. 30 felt strip is above the butt end of the shake it covers by 2 × weather exposure; example: 24-inch shakes at 10-inch exposure → 2 × 10 = 20 inches.Fastener length must penetrate through the roofing materials and not less than 3/4 inch into the roof sheathing; where sheathing is less than 3/4 inch thick, the fastener must penetrate through the sheathing.Nails of sufficient length to penetrate the deck not less than 3/4 inch or through the thickness of the deck, whichever is less.Cap nail length sufficient to penetrate through the sheathing or not less than 3/4 inch into it; shank not less than 0.083 inch (ring shank) or 0.091 inch (smooth shank).Tiles with an installed weight less than 9 pounds per square foot require not less than one fastener per tile regardless of roof slope, overriding a 'fasteners not required' entry in Table R905.3.7 (example: 7 psf tile over solid sheathing with battens at 4:12, non-snow → 1 fastener per tile).In areas subject to snow, not less than two fasteners per tile; the one-fastener-per-tile value from Table R905.3.7 for solid sheathing without battens applies only outside snow areas (example: 11 psf tile, 4:12, 110 mph, 20 ft above grade, snow area → 2 fasteners per tile).Slopes 4:12 or greater: single layer lapped 2 inches; where maximum basic design wind speed is 140 mph or greater, same application except all laps not less than 4 inches (example: 150 mph, 5:12 → 4-inch laps).Attach with corrosion-resistant fasteners in a grid pattern of 12 inches between side laps with 6-inch spacing at side and end laps (IRC R905.1.1 Exception 3.2; same 12-inch grid/6-inch side-lap pattern per IBC 1507.18.4.1 where Vasd is not less than 120 mph).Tabulated loads are published for a mean roof height of 30 feet in Exposure B (ASD); multiply the tabulated value by the height/exposure adjustment coefficient from Table R301.2(3).