NRCA Roofing Manual: Steep-Slope Roof Systems, 2025

The 2025 edition of the National Roofing Contractors Association (NRCA) Roofing Manual: Steep-Slope Roof Systems provides in-depth coverage of design, materials, installation and construction-details for steep-slope roof systems (defined generally as slopes exceeding 3:12) with dedicated sections on asphalt shingle, clay and concrete tile, metal shingle, slate, and wood shake/wood shingle roof systems. Notable updates from the 2021 edition include: • Revised minimum plywood sheathing thickness and elimination of oriented strand board (OSB) recommendation for steep-slope decks. • New guidance for non-wood deck and nailable substrate materials, updated high-wind region recommendations, and new Appendices addressing compliance with International Building Code (IBC) 2024 and International Residential Code (IRC) 2024. • A total of 234+ construction detail drawings across all five system types and supplemental content for slate repair and the Insurance Institute for Business & Home Safety (IBHS) FORTIFIED Roof™ program.This manual is published in hard-copy and digital formats and is recommended as a reference for roofing contractors, architects, designers and those studying for licensing or certification in the roofing trade.

The NRCA Roofing Manual: Steep-slope Roof Systems, 2025 manual provides you with valuable information about the design, materials and installation techniques applicable to steep-slope roof system applications. With five comprehensive sections—Asphalt Shingle Roof Systems, Clay and Concrete Tile Roof Systems, Metal Shingle Roof Systems, Slate Roof Systems, and Wood Shake and Wood Shingle Roof Systems—this manual is a welcome addition to your technical library.

Each section includes in-depth information about roof assembly configurations, roof decks, underlayments, materials, design and installation. Construction details are provided in each section as follows:

• Asphalt Shingle Roof Systems: 24 construction details
• Clay and Concrete Tile Roof Systems: 92 construction details
• Metal Shingle Roof Systems: 20 construction details
• Slate Roof Systems: 22 construction details
• Wood Shake and Wood Shingle Roof Systems: 76 construction details

Additionally, NRCA has updated and revised The NRCA Roofing Manual: Steep-slope Roof Systems—2025 content to maintain its position as an authoritative up-to-date industry reference. Notable changes include:

• New recommendations regarding other-than-wood roof deck and nailing substrate materials in steep-slope applications
• Revised recommendations for high-wind region steep-slope applications
• New and revised construction details
• Revised appendixes address steep-slope roof system compliance with IBC 2024 and IRC 2024 provisions
• New appendixes address roofing slate repairs and IBHS’s FORTIFIED RoofTM program