Cut away the damaged area.
Roof sheathing rot.
These thin sheets of wood absorb moisture when exposed to it through excess condensation or a roof leak.
Most roof decking also called sheathing is plywood or oriented strand board osb.
Some signs that roof sheathing is damaged or rotted include a sagging ceiling noticeable roof leaks and missing patches of roof shingles or tiles.
All roofs have a layer of plywood sheathing underneath them which provides a base for the shingle attachment.
While a single exposure to moisture is unlikely to lead to rot routine water exposure may.
If your gutters are broken that s also a sign that your sheathing is damaged as functioning gutters help prevent moisture accumulation.
Although the plywood typically lasts longer than most shingles and roof coverings leaks can cause them to rot.
You may need to cut a little extra to expose enough of the trusses and make sure you get rid of all the rotten wood.
Rotted plywood is identifiable by sinking areas of the roof or visible leaks.
When sheathing is exposed to moisture frequently there is always a chance it will decay or develop wood rot.
When replacing roof decking you first need to get rid of the old rotten section.
Nonetheless there are still telltale signs that indicate you have a sheeting issue.
Damaged shingles and rotted plywood must be removed before replacing them with new plywood and roofing material.
Wood sheathing will eventually rot as excess moisture continually collects on it and the material is unable to properly dry out.