How to Fix Rust Holes in a Metal Roof

Brush the roof surface around hole with a wire brush. Apply rust converter around the hole and wait for the rust converter to react with the rust and dry. Follow the manufacturer's recommended curing time.

Wipe the area surrounding the hole with a dry rag to remove loose particles and debris. Paint the surrounding area with an oil-based paint, using a paint brush. Allow the paint to dry. Follow the paint manufacturer's recommended drying time.

Apply a generous amount of roof cement over the hole, including the surrounding areas, if the hole is less than 1/4 inch in diameter. You can skip this process if the hole is 1/4 inch or more in diameter.

Cut a circular piece of metal sheet larger than the hole diameter by about 1/2-inch, using metal snips. If the roof surface is not flat, bend the circular metal sheet according to the shape of the roof surface.

Paint both sides of the metal sheet with oil based paint and allow the paint to dry.

Apply a layer of roof cement around the edge of the hole and cover the hole immediately with the metal sheet. Allow the roof cement to set for about an hour. After it sets, apply a new layer of roof cement over the metal sheet. Extend the cement application by about an inch around the area surrounding the metal sheet and allow the roof cement to dry.