Address any existing roof leaks and replace rotten rafters or.
Installing roofing over existing shingles.
But first here are a few precautions about the underlying material.
When roofing over your existing shingles can be a good idea.
A steel roof is a lifetime investment lasting 50 years or more if it s a good one.
Let s start with the good.
If conditions are right new shingles laid over old shingles can be just as attractive and durable as shingles laid on bare sheathing.
If you choose to install metal roofing over shingles there are certain things you must keep in mind.
The layers of felt should be overlapped by 1 inch as you work toward the roof ridge.
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.
The felt should be secured every six inches with nails or staples.
All shingle manufacturers honor the warranty whether their products are used for a reroof or a new roof.
Install a layer of roofing felt over the roof before you begin installing the new shingles.
But you must take care to install shingles correctly so they lie flat.
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.
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.
That s also why building codes commonly limit re roofing to no more than two layers.
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.
When you should tear off your roof and start from scratch instead.
This is what it looks like when you install a steel shingle roof system over an existing asphalt shingle roof.
Many arizona homeowners with shingle roofs do decide to roof over their existing shingles because.
Asphalt roofs typically last 20 to 30 years depending on the installation and shingle quality.
Why installing new shingles over old shingles can be good.