One of the biggest mistakes that many homeowners make is putting a metal roof over roofs that have existing problems. This may seem like a cost-effective solution to fixing your roof because metal roofs are thought to have a longer shelf life than traditional asphalt roofs, but in reality the only thing that is happening is putting a band-aid over the problem.
If you put a metal roof over your existing roof you will likely have problems. The problems consist of mold, mildew, and pest problems. We have already had dozens of jobs this year where we have had to fix metal roofs. We found that the real problem lies underneath the metal roof with the pre-existing condition of the old roof. This is a much bigger job than just spending the money to either fix the asphalt roof in the first place, or replace it with a new roof.
The roofing contractors who install these roofs are relying a little bit on the existing asphalt roof to provide for some of the protection. They allow moisture to get in. Sometimes pests such as termites get in. The idea of not having to replace your roof as often may sound like a fiscally glorious alternative. You are setting yourself up for a bigger financial blow. There are essentially two roofs that would need to be replaced in the future.
metal roofs done right
Do yourself a favor and either replace the entire roof with metal, or get your roof repaired by professionals who have a reputation for consistent quality service. Don’t settle on price. You will end up paying more in the long run.