Installing New Roof Over Old

To level out an existing asphalt shingle roof rip down reduce the height of two courses of shingles as shown in the drawing below.

Installing new roof over old.

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. But you must take care to install shingles correctly so they lie flat. Has the same manufacturer s warranty.

Installation is easier than for a tear off job because you can use the existing shingles as guides for laying the new ones. 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. A properly installed layover roof can look and function as well. Looks just as good and lasts as long.

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. If conditions are right new shingles laid over old shingles can be just as attractive and durable as shingles laid on bare sheathing. That s also why building codes commonly limit re roofing to no more than two layers.