When it comes to roofing projects, many homeowners are unsure as to whether or not they should have their asphalt shingles removed before installing new shingles.
A professional roofer can best answer the question.
However, asphalt shingles usually have a lifespan of 15 to 25 years.
It’s common to place two layers of shingles on top of one another, before laying a third layer. The general rule is to tear up both layers and then lay down a fresh layer.
However, a professional contractor may not feel comfortable laying a second layer of shingles over the first layer for several reasons.
The first layer of shingles should be thoroughly inspected by a roofer to determine if the first layer is severely damaged, cracked, uneven or buckled.
If there is damage, a contractor would never put a new layer over these shingles.
The reason is simple. The new layer of shingles will take on the same appearance as the first layer. If the first layer is uneven or doesn’t lay flat, the second layer will fail to lay flat as well.
Another factor to consider is the supporting structure of the frame. The roof must be able to support the weight of multiple layers. If the roofing contractor feels there will be too much weight, they will recommend removing the first layer.
In most cases, even with a perfect roof, very rarely will a roofer recommend installing a layer of shingle over two layers.