Roof Penetration

A roof penetration is any hole drilled through the roof surface to attach solar racking hardware to the underlying roof structure. Each penetration point is sealed with flashing to maintain the roof’s waterproof integrity.

A typical residential solar installation requires 30–60 roof penetrations, depending on the number of panels and the type of racking system used. Each penetration is made by drilling a lag bolt or structural screw through the roofing material (shingles, tile, etc.) into a rafter or truss. This is the standard method for securing solar panels and is proven to be safe and reliable when done correctly. Homeowners often worry about roof leaks from penetrations, but with proper flashing and sealant, leaks are extremely rare — reputable installers offer 10–25 year workmanship warranties covering any leak issues. Some mounting solutions minimize or eliminate penetrations entirely: standing seam metal roofs use non-penetrating clamps, flat roofs can use ballasted systems, and some newer racking designs reduce the number of attachment points needed. If minimizing roof penetrations is a priority, discuss options with your installer during the proposal stage.