It is not uncommon to see a roof with more than one layer of shingles. This is never a good idea. What is referred to as a “roof over” or a “reroof” is putting shingles over the top of an existing roof. As a rule, we do not do this for a variety of reasons.

Shingles are heavy. Putting a layer of shingles or roofing material over an existing layer adds a lot of weight to your structure. The additional weight can be more than the structure is designed to handle and can create a variety of problems. Multiple layers of shingles can make diagnosis of a roof leak almost impossible. Water can run in between the layers and drop through the old roof anywhere. In cold temperatures or times where there is snow on the roof, it can freeze in between the layers and damage both layers.

Removing the old shingles is always the best thing to do. It not only keeps the weight to a minimum, but also allows our team to identify structural problems with the decking underneath and repair it before we install the new roofing materials..