Intact roof sheathing is essential for both the integrity of the roof covering, as well as the overall roof structure. Roofing materials will not secure properly to deteriorated sheathing. The sheathing stabilizes the roof framing, adding strength to it and creating a complete system. While safety comes first, an effort should be made to view as much of the roof sheathing as possible.
Inspect for any signs of water penetration. Stains, deterioration, openings to daylight, damaged or loose boards, and delaminated plywood should be reported. The presence of suspected fire-retardant plywood (FRT plywood) should be reported. Inspect for any significant number of fasteners that have missed attaching the roof decking to the rafter or truss. Look for “H-Clips” on sheet sheathing at the mid-point between rafters or trusses. They are advised, but not absolutely required, on sheathing <7/16″ installed on 24″ centers.
There are moisture stains on the sheathing. This indicates water penetration. Identify and mitigate the source of water penetration.
There is damaged sheathing. This affects the strength of the sheathing and the proper installation of the roofing materials. The cause of the damage must be identified. Hire a roofing contractor for an evaluation and to make repairs as needed.
There is buckled or sagging sheathing. This affects the strength of the sheathing and the proper installation of the roofing materials. Replace the sheathing.
There is delaminated sheathing. This affects the strength of the sheathing and the proper installation of the roofing materials. Replace the sheathing.
There is deteriorated sheathing. This affects the strength of the sheathing and the proper installation of the roofing materials. The cause of the deterioration must be identified. Hire a roofing contractor for an evaluation and to make repairs as needed.
There are missing H-Clips at the edges of the roof sheathing. Clips function to anchor the sheathing sections to one another and prevent sagging. Replace the fasteners as needed.
Fire-rated materials are missing in the first 4′ of roof sheathing next to the party wall. This is required to prevent flame spread from the adjacent unit. Install fire-rated materials as needed.
The roof sheathing appears to contain fire-retardant plywood (FRT plywood). This older product is subject to deterioration and weakening due to heat buildup in the attic. Hire a contractor for an evaluation and repairs/replacements as needed.
