How to Repair a Sheet Metal Roof

What You'll Need
Sheet Metal Patch
Soldering Gun
Roof Coating
Membrane Fabric Patch
Roof Caulk

A sheet metal roof is used widely by homeowners, due to its longevity and durability. However, harsh weather conditions can still puncture and damage the roof. Before the damage becomes worse, repair the roof right away with the instructions below.

Step 1 – Preparations

Visually inspect the sheet metal roof to check the extent of damage. Check if there are any punctured holes or cracks on the surfaces. If the damage is minimal, repainting is sufficient. If there are small narrow cracks, use a fabric membrane patch to cover the damage. For bigger damages, use a metal patch.

Clean the surface around the damaged area first before working on repairs,. Remove any peeling paint, scrub away grime and dirt, and wash the entire area to get rid of anything that will interfere with the patching repair.

Step 2 – Repairing Small Cracks

A membrane fabric patch is the best material to use to repair small cracks in the roof. How to use it: the fabric is to be sandwiched between 2 coats of roof coating. Apply the first coat of roof coating liberally on top of the damaged portion of the roof. The coat should extend at least 2 inches from the crack on all sides. Cover the first coat with the membrane fabric patch just after application. Do not do so when it has cured already. The membrane should also be at least 2 inches in width, to ensure that the crack gets covered entirely. Apply a second coat of roof coating on top of the membrane.

Step 3 – Patching with Sheet Metal

Determine the dimensions of the sheet metal patch. It should extend at least 2 inches from the puncture. Cut the metal sheet patch to size using metal shears. Be careful when dealing with sharp objects. Always use protective gloves.

Apply soldering flux on the edges of the patch and the perimeter around damaged roof where the edges of the patch will make contact. Position the patch in place and put a weight on top of it to hold it down (a brick for example). Place the solder at the edges of the patch and heat up the soldering gun. Let the soldering gun heat the solder. Allow the heated solder to seep into the underside of the patch. Solder around the entire perimeter of the patch, leaving no space open.

Double check for any unsoldered spaces. Re-apply solder if necessary. Wait for the solder to cool off. Apply a liberal amount of roofing coat on the edges of the patch. The coat should extend at least 2 inches from both the inside and the outside of the edges as well. Let the roof coating cure depending on the manufacturer’s instructions.

Step 4 – Repaint the Roof

To hide any of the patch repairs and to repair minor scratches in the roofing paint, repaint the entire roof or the portion of the roof that was repaired.