Metal-Roofs are more likely to be found on commercial buildings, farm structures or copper was used on older more stately buildings. Copper is commonly used to add a decorative touch to homes because of the green patina copper roofs form over time. Metal-Roofs are made from many different types of metal including tin, corrugated steel and aluminum. Damage to Metal-Roofs can occur from falling debris such as a tree branch, salt air and the use of different types of metals together. Using one metal type or fastener with a different Metal-Roofing sheet will cause electrolysis which is a chemical reaction between the two different materials. Electrolysis causes a roof to develop holes, pitting and weaken the structural integrity of the roof as a whole. Whenever repairing a Metal-Roof, always use the same metal type up against the existing panels and use the same type of metal fastener to avoid damage.
There are several methods that can be used when repairing a Metal-Roof.
For Pitting Metal-Roofs:
Sweep and vacuum the entire roof to remove as much excess dirt, dust and debris.
Buy an asphalt based liquid sealant. These sealants are made for Metal-Roofs and are available at hardware stores, home improvement stores and roofing supply stores.
Begin at the furthest corner away from your ladder.
Use a stiff bristle push type broom.
Pour liquid sealant over approximately a 3 foot by 3 foot area and use the push broom to spread an even coat over the entire roofing surface.
Patching a Hole in an Aluminum Roof:
Buy fiberglass screening material at a roofing supply store, hardware store or home improvement store.
Cut 2 pieces approximately 2 inches larger than the hole in all directions.
Use a wire brush and vigorously scrub the area surrounding the hole to remove excess dirt and debris.
Paint roofing cement around the hole.
Firmly press the fiberglass mesh patch in place.
Apply a thick coat of roofing cement over the top of the mesh and extend about an inch or 2 past it. As you extend the roofing cement allow the outer edges to become a thinner coat.
Place the second patch over the wet roofing cement and press it in.
Add another thick coat of roofing cement to cover the fiberglass mesh.
A patch can also be soldered in place, but should only be done by a do it yourselfer with soldering experience or by a roofing professional.