Putting A New Roof Over An Old One

Check your local ordinances to see whether this is even a possibility before moving forward with the project.

Putting a new roof over an old one.

Installing a new roof over an existing one also called a layover or nailover is often possible although not always the best option. Then we ll look a lot more reasons why you might not want to do this. The answer is yes you can lay new roof shingles over old ones. When a home receives this classification it is illegal to install a new asphalt roof over an existing one.

A properly installed layover roof can look and function as well. You re better off removing the old roof. Current shingles are curling or in bad shape the new shingle roof should lay flat on your old one. Unfortunately it s not an option for everyone.

The goal is to provide a reasonably flat surface for the new shingles to lie over with no gaps greater than 1 2 inch. If a shingle is torn or cracked glue the broken piece back in place using roofing cement. When you recover your old roof stays and the new roof gets installed on top. But if the current roof is curling this isn t possible.

With a traditional roof replacement we completely tear off your old roof and install a shiny new one in its place. A roof deck is an underlayment that shingles are laid on top of. Roofing over your existing roof is not always possible. So if there are already two layers the choice is made for you.

By adding shingles on top of the old roof there is no opportunity to inspect the roof deck to ensure that the current wood is not wearing out. Now that we ve taken care of the primary question at hand we ll consider a couple of reasons why you might want to do this.