Re Roofing Over Architectural 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.

Re roofing over architectural shingles.

This article series discusses best practices in the selection and installation of residential roofing. The standard practice is to limit to a total of two layers of shingles. Asphalt shingles can be laid over cedar shakes or shingles however this is a roofing project best left to pros. If you re going strictly via code you can install a layer over a layer.

All shingle manufacturers honor the warranty whether their products are used for a reroof or a new roof. Re roofing may affect the warranty on the new shingles. Re roofing with 3 tab shingles are pretty straight forward. Beveled wood pieces called horsefeathers must be laid along the thick edges of the shakes to make a fairly flat surface.

While both types are made up of the same essential components re roofing over architectural shingle is a different case altogether. Roofing second layer of shingles roofing. The quick answer is yes you can re roof architectural shingles over existing architectural shingles however you must check with the shingle manufacturer as well. Asphalt roof shingle re roofing advice.

However we wouldn t recommend this practice. Statistics by the national roof contractors association show that nine out of ten roofs in the us fail due to a ventilation issue. How to shingle over existing shingles and how to shingle a roof how to install roof shingles shingle layout lines h. This article discusses how to prepare an existing asphalt shingle roof for a roof over or for re roofing with new asphalt shingles.

If you look at the picture above you can see the difference. After that you should tear off old shingles before installing a new layer. Three tab shingles are a constant thickness while architectural shingles have multiple layers that create an uneven surface. Be sure to check with the shingle manufacturer regarding all warranty issues and installation requirements before re roofing.

Two layers is the maximum in most areas but some building codes allow only one.