DIY: Sealing Leaks in a Metal Roof

Sealing a leak in a metal roof can be quickly accomplished in a few hours on a warm day. These instructions should be used for roofs on barns, sheds, and other secondary buildings. For other leaks, especially those on your house's metal roof, it is best to call a professional. Often, your warranty should cover these sorts of leaks.

Step 1: Locate the holes in the metal roof that are causing the leaks. Mark them with tape and continuing until you have inspected the entire roof for problem areas.

Step 2: Remove any rust, dirt, and other debris from the surface of the metal roof using a wire brush. For larger flakes of dirt or rust, you can use a stiff bladed metal putty knife. Clean the area until clean shiny metal is present. Wipe down the area with a dry rag.

Step 3: Place a ring of butyl tape around each hole. The butyl tape should frame the hole in the metal roof with at leach 2 inches between the tape and hole. A simple rectangle of tape around the hole causing the leak is all that is required. Be sure to overlap the tape at the corners.

Step 4: Cut a piece of galvanized metal that will cover the rectangle created by the butyl tape. The galvanized metal patch should completely cover the tape as well as the hole. Use snips to cut the patch.

Step 5: Place the patch over the hole in the metal roof.

Step 6: Screw through the galvanized metal patch on the roof and into the butyl tape below. Place a screw in each corner of the patch, and space screws every 3 to 4 inches as needed.

Step 7: Cover each screw head with roofing cement. Also apply a bead of roofing cement around the perimeter of patch on the metal roof.

TIP: Roofing cement is available in tubes that will fit into a standard caulking gun.

Step 8: Paint on a roof coating guaranteed to protect against rust onto the the patch and extending slightly past the patch.

TIP: If your roof does not already have a coating to protect against rust and further leaks, clean the roof thoroughly and apply a coat over the entire roof using a paint roller.