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Property Types & Construction

Roof Sheathing

Definition and meaning of Roof Sheathing in real estate.

Roof sheathing consists of flat boards, typically plywood or oriented strand board, that are nailed directly to a roof's rafters to create a solid base for the shingles or other roofing materials.

In more detail

Also known as roof decking, sheathing plays a vital structural role by bracing the rafters and distributing weight across the roof. It provides the necessary surface for fasteners to hold shingles, tiles, or metal panels in place. If water leaks through the outer roofing layer, the sheathing can rot, swell, or sag, compromising the integrity of the entire roof system.

During a home inspection, appraisers and inspectors check the attic to ensure the sheathing is dry and free of mold or damage.

Key facts

CategoryProperty Types & Construction
Also known asRoof decking
Typical materialsPlywood or oriented strand board (OSB)
Watch out forSoft spots, saggy areas, water stains, and mold indicating leaks
Example

A homeowner hiring a contractor for a roof replacement learns that several sheets of roof sheathing have rotted due to a slow leak, requiring new plywood panels before the new shingles can be installed.

Frequently asked questions

What is the difference between roof sheathing and roof decking?

There is no practical difference between the two terms. Both refer to the structural wood layer that covers the rafters and supports the shingles.

Can you shingle directly over old sheathing?

Yes, as long as the old sheathing is dry, structurally sound, and free of rot. Any damaged or decayed boards must be replaced before installing new underlayment and shingles.

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