Replacing a roof can be very expensive. A second layer can be installed easily and affordably. However, there are some drawbacks to putting an extra layer of shingles on your roof.
The second layer of shingles can trap heat, which can result in the decomposition of both roof layers. The extra layer can reduce your roof’s lifespan by up to 40%. In addition, when you add the second layer, it can add extra weight to your roof. This can add stress and damage to your original roof and home structure.
Home inspectors will often report if they see a two or more layer of shingles. This can reduce the value of your home, and can be problematic if you are planning to sell your house.