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Steep- and Low-Slope Roofing Materials
Roofing material categories suited to steep- and low-slope roofs.
Copper Roof
Architectural copper roofing installed as standing-seam, batten-seam, flat-lock, or shingle systems. A premium, extremely long-lived metal that develops a protective green patina over decades.
Corrugated Metal Panel
Wavy or ribbed metal panels (typically galvanized or Galvalume steel, sometimes aluminum) fastened through the face with exposed screws. An economical exposed-fastener metal roof common on agricultural, industrial, and budget residential roofs.
Roof Cement and Mastic
Roof cement, also called plastic cement or flashing cement, is a trowel-grade asphalt-based mastic used to seal flashing laps, felt seams, and penetrations on steep- and low-slope roofs. Modern products are formulated asbestos-free under ASTM D4586, Standard Specification for Asphalt Roof Cement, Asbestos-Free, in Type I or Type II asphalt and Class I (dry) or Class II (wet) grades. Its older sibling, ASTM D2822, covered the asbestos-containing predecessor product and was withdrawn in 2016, though IRC Table R905.9.2 still lists D2822, D3019, and D4586 together as accepted asphalt cements for built-up roof coverings. IRC Section R905.6.6 separately requires a plastic-cement top coating on cap flashing where slate roofing meets chimneys or masonry walls.
Roofing Screws and Fasteners
Roofing screws are threaded, typically self-drilling and self-tapping fasteners with integrated washered heads, used to mechanically attach exposed-fastener metal roof panels to purlins or decking and to secure insulation, cover boards, and single-ply membrane in low-slope mechanically-attached systems. Unlike smooth-shank roofing nails, these fasteners are governed less by a single material standard than by the tested roof assembly: FM Approvals Standard 4471 (Class 1 Panel Roofs) qualifies metal panel systems, including fastener type and spacing, as a complete wind-uplift assembly, while FM Approval Standard 4470 sets the corrosion-resistance test fasteners must pass for low-slope attachment. Some self-drilling steel screws also reference ASTM C1513, which covers steel tapping screws for cold-formed steel framing connections. Correct selection means matching the screw named in the specific FM or UL assembly listing being installed, not a generic product spec.
Standing-Seam Metal Roof
Interlocking vertical metal panels with concealed fasteners and raised seams, typically steel or aluminum. A premium, long-life steep-slope and low-slope system.
Zinc Roof
Architectural zinc roofing, typically titanium-zinc alloy, installed in standing-seam or flat-lock panels. A premium European metal prized for its self-healing patina and very long life.