In many cases, roofing sheets can be installed over an existing roof structure if the base frame is stable and free from major damage.

This method can save demolition time and reduce disruption during renovation projects.

Before re-roofing, it is important to inspect the old roof for leakage, corrosion, sagging, and structural weakness.

Additional support or correction may be needed if the original roof is uneven or overloaded.

A proper site inspection helps determine whether overlay installation is practical or if a full replacement is the safer option.