Manufacturers will still.
Problems with re roofing a house over existing shingles.
Diminish the overall life of the roof.
Before considering layering roofing over an existing roof it s important to check your local building codes.
All shingle manufacturers honor the warranty whether their products are used for a reroof or a new roof.
Reroofing is the process of layering one set of new shingles over a set of existing shingles.
Looks just as good and lasts as long.
Nailing new shingles over existing ones is less expensive and faster requiring less labor but it also means you lose the chance to assess the sheathing for signs of water damage.
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.
Hope you like it.
It can only be done once so if you already have two layers of roofing in place reroofing is not an option for you.
This article series discusses best practices in the selection and installation of residential roofing.
We also discuss proper asphalt shingle roof preparation for a roofover job.
Re roofing may affect the warranty on the new shingles.
This article discusses how to prepare an existing asphalt shingle roof for a roof over or for re roofing with new asphalt shingles.
Because there is no tear off reroofing can go much faster and be much less expensive than a complete roof replacement.
Many restrict a number of times you can layer the roofing.
Asphalt shingles can be laid over cedar shakes or shingles however this is a roofing project best left to pros.
However layering roofing can.
Add excessive weight to the structure of your house.
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.
Local codes might not allow re roofing.
Has the same manufacturer s warranty.
Installing a new roof over shingles takes less time than tearing off the old roof.
Before you reshingle a roof read our step by step guide for adding new shingles over old ones.
In fact the only pro to a shingle over is it s cheaper and cleaner.
Void your shingle warranty.
Two layers is the maximum in most areas but some building codes allow only one.
Beveled wood pieces called horsefeathers must be laid along the thick edges of the shakes to make a fairly flat surface.
If your roof is in good shape but has some damage to one side from a downed tree or has lost shingles in a wind storm an overlay is worth considering.
Here is a video on how we lay a second layer of asphalt shingles over existing asphalt shingles.
Asphalt roof shingle re roofing advice.
