Roofing Over Existing Shingles

Building officials in some areas will only allow a re roof over one layer of shingles while officials in other places may allow you to place the roof over two layers of shingles.

Roofing over existing shingles.

When roofing over your existing shingles can be a good idea when you should tear off your roof and start from scratch instead. In fact the only pro to a shingle over is it s cheaper and cleaner. Installation is easier than for a tear off job because you can use the existing shingles as guides for laying the new ones. Re roofers have tricks to lay new roof shingles over old so that the same step ups between courses are maintained but if any old shingles are cupped curled or otherwise misshapen those defects will telegraph through to the new layer.

Yes you can install a metal roof over shingles. 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. Why installing new shingles over old shingles can be good let s start with the good. But you must take care to install shingles correctly so they lie flat.

If conditions are right new shingles laid over old shingles can be just as attractive and durable as shingles laid on bare sheathing. Although it sounds like a good idea we can assure you the cons heavily outweigh the pros.