Installing New Roof Over Old

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 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. A properly installed layover roof can look and function as well. But you must take care to install shingles correctly so they lie flat. Installing a new roof over an existing one also called a layover or nailover is often possible although not always the best option.

Leave the old valley flashing in place and install new over it. Has the same manufacturer s warranty. Along the rakes install a new j channel drip edge which wraps around the old rake flashing and starter courses. 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. 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. As long as it s done right and under the right conditions installing new shingles over old ones can last as long and look just as good as a complete re roof.