New Roof Sheathing Over Old

Nailing new shingles over existing ones is less expensive and faster requiring less labor but it also means you lose the chance to assess the sheathing for signs of water damage.

New roof sheathing 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. If your roof is in good shape but has some damage to one side from a downed tree or has lost shingles in a wind storm an overlay is worth considering. The existing asphalt shingles need replacement so he plans to do a tear off and re shingle. But you must take care to install shingles correctly so they lie flat.

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. Looks just as good and lasts as long. That s also why building codes commonly limit re roofing to no more than two layers.

That must always be accounted for in the roofing design process. 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. Answered 6 years ago by wowhomesolutions. Construction of a new roof deck for asphalt fiberglass roofing if you re going to add a roof on top of an old one it s a good idea to remove any loose shingles and apply a new layer of 30 pound roofing felt before laying the new shingles.

Find a pre screened local roofing contractor. The new plywood thickness should be. Installation is easier than for a tear off job because you can use the existing shingles as guides for laying the new ones. As long as the new plywood itself can span the distance and carry the roof wind seismic and snow loads for your region adding new ply over old is just fine.