Remove The Old Roof Or Roof Over
As a Lancaster Roof Contractor I have come across people asking the question:
“If I only have one layer of shingles on my roof can I just re-roof over my existing roof? “
People are getting mixed information about this concept. I strongly discourage this practice for the main reason (most professionals don’t mention) which is it completely voids the warranty on the product you are installing.
GAF and some other leading brands of architectual shingle manufactures are starting to offer lifetime warranties on their previously 30yr rated shingles. Some codes do allow for a roof over, but in my opinion it is not worth the minimal amount saved to void a warranty on a great product