Re Shingling A Roof Over Old Shingles

This will help keep any moisture from getting under the felt.

Re shingling a roof over old shingles.

Most building codes allow for two layers of asphalt shingles on a house so stripping off everything down to the plywood sheathing may not be your only choice. Has the same manufacturer s warranty. 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. That s also why building codes commonly limit re roofing to no more than two layers.

Installation is easier than for a tear off job because you can use the existing shingles as guides for laying the new ones. Roofing over your existing roof is not worth it if you haven t noticed yet we are not fans of shingle overs not at all. Looks just as good and lasts as long. This process starts with a 5 inch starter strip fit along the eaves and set against the second course of existing shingles see figure 2 16.

Install a layer of roofing felt over the roof before you begin installing the new shingles. If laying three tab shingles over three tab shingles it is important to nest the new shingles against the old to create a flat surface as friedman elaborates just below. If conditions are right new shingles laid over old shingles can be just as attractive and durable as shingles laid on bare sheathing. The layers of felt should be overlapped by 1 inch as you work toward the roof ridge.

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. All shingle manufacturers honor the warranty whether their products are used for a reroof or a new roof. Find a pre screened local roofing contractor.

Not only will the existing layer provide a secondary back up roof for the new shingles but it will also save the cost and inconvenience of removing and disposing or recycling the old shingles. Now everything is trapped under the 2nd layer of shingles again having the potential to shorten the lifespan of the top layer of shingles. The felt should be secured every six inches with nails or staples. If the job is done correctly with the new layer of shingles laid flat over the existing shingles the old roof cushions the new one and serves as a secondary barrier should wind or water ever break through the new shingles.

Call for free estimates from roofing pros now. Installing a new roof over shingles takes less time than tearing off the old roof. We don t recommend them nor do we do them.