Roof Sheathing Rot

Although the plywood typically lasts longer than most shingles and roof coverings leaks can cause them to rot.

Roof sheathing rot.

When replacing roof decking you first need to get rid of the old rotten section. 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. Wood sheathing will eventually rot as excess moisture continually collects on it and the material is unable to properly dry out.

Nonetheless there are still telltale signs that indicate you have a sheeting issue. All roofs have a layer of plywood sheathing underneath them which provides a base for the shingle attachment. These thin sheets of wood absorb moisture when exposed to it through excess condensation or a roof leak. Some signs that roof sheathing is damaged or rotted include a sagging ceiling noticeable roof leaks and missing patches of roof shingles or tiles.

Cut away the damaged area. For starters you may notice a leak in your ceilings that originated from your roof. As mentioned it is near impossible to see roof sheathing making it very hard to determine when it starts to rot. Damaged shingles and rotted plywood must be removed before replacing them with new plywood and roofing material.

While a single exposure to moisture is unlikely to lead to rot routine water exposure may. 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.