Installing Roofing Over Existing Shingles

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 roofing over existing 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. But you must take care to install shingles correctly so they lie flat. Installation is easier than for a tear off job because you can use the existing shingles as guides for laying the new ones.

Asphalt roofs typically last 20 to 30 years depending on the installation and shingle quality. Address any existing roof leaks and replace rotten rafters or. Installing a new roof over an existing one also called a layover or nailover is often possible although not always the best option a properly installed layover roof can look and function as well. We re going to break them down so you know what to look out for.

Let s start with the good. Doesn t provide the flattest surface for the metal roofing to be installed over each course of shingles is about a 1 8 higher than the course just below it. A steel roof is a lifetime investment lasting 50 years or more if it s a good one. 3 install 1x4 purlins down over the shingles before installing the metal roof the third way to install a metal roof over shingles is by applying 1x4 purlins over the shingle roof.

All shingle manufacturers honor the warranty whether their products are used for a reroof or a new roof. When roofing over your existing shingles can be a good idea. The felt should be secured every six inches with nails or staples. If conditions are right new shingles laid over old shingles can be just as attractive and durable as shingles laid on bare sheathing.

Install a layer of roofing felt over the roof before you begin installing the new shingles. The layers of felt should be overlapped by 1 inch as you work toward the roof ridge. If you choose to install metal roofing over shingles there are certain things you must keep in mind. Many arizona homeowners with shingle roofs do decide to roof over their existing shingles because.

But first here are a few precautions about the underlying material. Installation of metal roofing over shingles.