Installing a metal roof directly over existing asphalt shingles is a roofing technique that involves placing a new metal roof system on top of an existing shingle roof, rather than removing the old roofing material. This process can potentially reduce labor costs and disposal fees associated with traditional roof replacement. However, specific building codes and the condition of the underlying shingles significantly influence its feasibility. The integrity of the original roof must be assessed to ensure it can adequately support the additional load of the metal roof.
The practice offers several advantages. It can provide enhanced insulation, noise reduction, and fire resistance. Furthermore, it minimizes disruption to the building occupants during installation, compared to a complete roof tear-off. Historically, this method gained traction as a cost-effective alternative in situations where complete roof replacement was not economically viable or structurally necessary. However, it’s crucial to acknowledge that this approach may void certain manufacturer warranties on the metal roofing system if installation guidelines are not strictly adhered to.