This project shows the tear off of an old roof and what we often find underneath the existing materials. Often, decking or boards are weathered or rotten, and need to be replaced. Putting new materials on top of a bad roof surface leads to problems such as leaks or roof failure.
As long as the plywood is good and stays dry, it can last forever but once our professional roofers have fixed the underlying cause of the moisture, they will need to replace all the wood affected by the dry or wet rot.
When your plywood decking is rotting, you have a big problem and you’ll need a contractor to fix it for you. One of the biggest warning signs would be a water spot on your ceiling. If the spot gets bigger you’ll have to check it out and head up to the attic for more clues.