Problems With Re Roofing A House 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.

Problems with re roofing a house over existing shingles.

Roofing over your existing roof is not worth it if you haven t noticed yet we are not fans of shingle overs not at all. 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. Your roof is soft and spongy feeling if when walking on your roof the majority of it feels soft and spongy you may have some problems with the underlying sheathing of the roof. Here is a video on how we lay a second layer of asphalt shingles over existing asphalt shingles.

Before you reshingle a roof read our step by step guide for adding new shingles over old ones. We also discuss proper asphalt shingle roof preparation for a roofover job. This article discusses how to prepare an existing asphalt shingle roof for a roof over or for re roofing with new asphalt shingles. Re roofers have tricks to lay new roof shingles over old so that the same step ups between courses are maintained but if any old shingles are cupped curled or otherwise misshapen those defects will telegraph through to the new layer.

This article series discusses best practices in the selection and installation of residential roofing. Asphalt roof shingle re roofing advice. Beveled wood pieces called horsefeathers must be laid along the thick edges of the shakes to make a fairly flat surface. All shingle manufacturers honor the warranty whether their products are used for a reroof or a new roof.

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. Because you aren t lifting up the existing shingles you can t know for certain what the roof deck looks like. The third layer of shingles will be too heavy to be supported. While most problems can be spotted before the shingles are torn off occasionally there is rot or sagging that is not apparent beneath the shingles.

We don t recommend them nor do we do them. To fix it you ll need to remove the existing roof. Continue reading below our video of the day. Asphalt shingles can be laid over cedar shakes or shingles however this is a roofing project best left to pros.

Now everything is trapped under the 2nd layer of shingles again having the potential to shorten the lifespan of the top layer of shingles.