Asphalt T-lock Shingles

When is a new roof not a new roof? When it has been placed over three layers of old roofing.

Asphalt shingle roofs are allowed a maximum of two layers before the roof needs to be stripped down to the structure to begin again.

More than two layers places undue stress on the structure, will deteriorate quicker, and is more likely to leak because of re-used flashings.