Roof Assemblies and Rooftop Structures
Roof covering materials, drainage, and rooftop structures
Sections
Scope — Roof Assemblies and Rooftop Structures
Establishes the scope of Chapter 15, governing design, materials, construction, and quality requirements for roof assemblies and rooftop structures.
Definitions — Roof Assemblies
Directs users to Chapter 2 for definitions of key roofing terms used throughout Chapter 15, including various roof covering types, assembly components, and reroofing terminology.
Weather Protection
Requires roof decks to be covered with approved coverings, secured per Chapter 15 and manufacturer instructions, to protect the building or structure.
Flashing
Requires flashing at all wall-roof intersections, gutters, slope changes, direction changes, and roof openings. Metal flashing must be corrosion resistant, minimum No. 26 galvanized sheet gage (0.019 inch).
Coping
Parapet walls must have coping made of noncombustible, weatherproof materials at least as wide as the parapet wall thickness.
Roof Drainage
Roof drainage design and installation must comply with the International Plumbing Code Section 1502.
Wind Resistance of Roofing
Roof coverings, decks, and framing must be designed for wind loads per Chapter 16. Roof coverings must be tested for wind resistance per Section 1504.1.1.
Wind Resistance Test Standards
Roof coverings must pass wind resistance testing per the applicable standard listed in Table 1504.1.1, and where applicable, meet Section 1609.5.2 requirements.
Fire Classification
Roof coverings must have a fire classification per Table 1505.1 based on building construction type. Classification determined by ASTM E108 or UL 790 testing.
Roof Covering Application — General
Roof coverings must be installed per this section and manufacturer instructions. Must resist component and cladding wind loads per Chapter 16.
Built-Up Roofing
Built-up roofing must comply with applicable ASTM standards (D6509, D2178, D4601, or D6162), installed per this section and manufacturer instructions.
Underlayment Requirements
Underlayment must comply with ASTM D226 Type I, ASTM D4869 Type I, or ASTM D6757 unless otherwise specified for specific roof covering types. Self-adhering underlayment must meet ASTM D1970.
Modified Bitumen Roofing
Modified bitumen roofing must comply with applicable ASTM standards (D6162, D6163, D6164, or D6222), attached per manufacturer instructions.
Ice Barrier Requirements
In cold climates (January avg temp ≤ 25°F), ice barriers of cemented double underlayment or ASTM D1970 self-adhering membrane must extend from the eave at least 24 inches past the exterior wall line.
Thermoset Single-Ply Roofing
Thermoset single-ply roofing (e.g., EPDM) must comply with ASTM D4637 or D5019, installed per this section and manufacturer instructions.
Thermoplastic Single-Ply Roofing
Thermoplastic single-ply roofing (e.g., TPO, PVC) must comply with ASTM D4434, D6754, or D6878, installed per this section and manufacturer instructions.
Sprayed Polyurethane Foam Roofing
Sprayed polyurethane foam roofing must comply with ASTM C1029 and be protected from the exterior environment by an approved coating or covering.
Liquid-Applied Roofing
Liquid-applied roofing must comply with applicable ASTM standards (C836, C957, D1227, or D6083), installed per this section and manufacturer instructions.
Photovoltaic Modules/Shingles
Photovoltaic modules/shingles used as roof coverings must be listed per UL 7103 or UL 1703, installed per manufacturer instructions and this section.
Asphalt Shingles
Asphalt shingles must comply with ASTM D3462 or D7158, be self-sealing, interlocking, or cemented/fastened per manufacturer. Wind resistance tested per ASTM D7158.
Clay and Concrete Tile
Clay and concrete roof tiles must meet standards in Table 1507.3, be installed per manufacturer instructions, and attached per Section 1507.3.7.
Metal Roof Panels
Metal roof panels must meet Table 1507.4 standards, installed per manufacturer instructions on solid/closely fitted deck unless designed for spaced supports.
Metal Roof Shingles
Metal roof shingles must meet Table 1507.5 standards, installed per manufacturer on solid or closely fitted deck.
Slate Shingles
Slate shingles must comply with ASTM C406, installed on solid sheathing with minimum headlap of 4 inches (8:12 to <20:12 slope) or 3 inches (20:12+ slope).
Wood Shingles
Wood shingles must meet Table 1507.8 standards, installed on solid or spaced sheathing. Spaced sheathing boards minimum 1x4, spaced at weather exposure.
Wood Shakes
Wood shakes must meet Table 1507.9 standards, installed on solid or spaced sheathing with No. 30 felt interlayment (18" wide) between each course.