Installing New Roof Over Old

Manufacturers will still warranty the roof for the same amount of time as a re roof as long as it s done by a qualified installer.

Installing new roof over old.

If conditions are right new shingles laid over old shingles can be just as attractive and durable as shingles laid on bare sheathing. Has the same manufacturer s warranty. But you must take care to install shingles correctly so they lie flat. Along the rakes install a new j channel drip edge which wraps around the old rake flashing and starter courses.

Leave the old valley flashing in place and install new over it. A properly installed layover roof can look and function as well. Looks just as good and lasts as long. Installing a new roof over an existing one also called a layover or nailover is often possible although not always the best option.

Installing new roof shingles over old effectively doubles the weight of the roofing so you have to make sure your roof structure can handle the extra load. Installing a new roof over shingles takes less time than tearing off the old roof. To level out an existing asphalt shingle roof rip down reduce the height of two courses of shingles as shown in the drawing below.