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.
Roofing over old shingles instructions.
Roofing second layer of shingles roofing.
Yes you can and by doing so you save in the labor and hassle of tearing off the old roof and you won t be contributing to filling our landfills.
Adding new roofing over old sometimes called a re roof is possible only with asphalt shingles also called composition shingles.
Remove the metal flashing.
But before we get started one thing must be clear.
Beveled wood pieces called horsefeathers must be laid along the thick edges of the shakes to make a fairly flat surface.
Before you reshingle a roof read our step by step guide for adding new shingles over old ones.
A benefit to doing it this way is that you can see if there is any rotten plywood that needs to be replaced before installing the new roof.
Prep work for re roofing over asphalt shingles.
Can i install a new metal roof over shingles.
1 remove the shingles before installing the metal roof the first way to install a metal roof over shingles is by completely removing the old shingles before installing the new metal roof.
Bring a trash can up on the roof so you have a place to throw old shingles and flashing.
You can t do it with wood or slate for example and you should never mix materials such as laying asphalt shingles over cedar shakes.
Begin by removing the shingles using a roofing shovel.
All shingle manufacturers honor the warranty whether their products are used for a reroof or a new roof.
Installing a new roof over an existing one also called a layover or nailover is often possible although not always the best option.
Asphalt shingles can be laid over cedar shakes or shingles however this is a roofing project best left to pros.
How to install a roof over an existing roof.
Inspect the condition of the existing roof and roof deck for numer of roof layers soundness of roof decking smoothness of existing roof installation and other factors that determine whether or not you can do a roof over or if a roof shingle tear off is required.
Although it sounds like a good idea we can assure you the cons heavily outweigh the pros.
Next remove old shingles and flashing.
When contemplating a new roof many people hope to simply do a shingle over and avoid the extra cost and mess of tearing off the existing roof and starting from scratch.
Use caution so you don t damage any windows or siding in the process.
In fact the only pro to a shingle over is it s cheaper and cleaner.