How to Repair a Standing Seam Metal Roof

A man cleans a roof.
  • 1-2 hours
  • Intermediate
  • 50-200
What You'll Need
Oxygen bleach
Paint stripper
Medium grit sandpaper
Sheet metal patch
Sheet metal screw set
Roof caulk
Acrylic roof coating
Butyl tape
Putty knife
Wire brush
Tin snips
Roof paint
Flexible polyester fabric

A standing seam metal roof is designed for durability and strength, but sometimes, it can still get damaged due to impact caused by a falling tree branch or a storm. Below are steps on how to repair it.

Step 1 - Assess the Damage

Climb up the roof for visual inspection. If a foreign object punctures the roof, the damage requires patching. If the surface is merely scratched, the application of a good roof coating product is sufficient.

Step 2 - Prep the Area

Whatever repair method you use, it is necessary to prep the area so that the patch, coating, or paint that will be applied will adhere firmly on the surface. To do so, wash the area with a detergent solution and then rinse with water. Next, mix oxygen bleach and water at 50:50 ratio and use it to remove organisms such as mold or algae from the surface, which can affect the adhesion of the patch, coating, or paint. Allow it to dry. Apply paint stripper on the area and then scour loose paint and the primer using a putty knife. Use a wire brush if necessary. Sand the surface afterward, using medium grit sandpaper.

Step 3 - Try the Membraning Method

The membraining method is fit for small, narrow cracks only, especially for small dents in the seams. Go to Step 4 for punctured holes wider than 1 inch in diameter.

Prep the area as described above. Next, apply a sufficient amount of acrylic roof coat at least 2 inches wide on both sides of the crack. Before the coating dries, cut flexible polyester fabric designed for roof patching, at least 2 inches wider than the area of the seam requiring a patch repair. Place the fabric directly on top of the coating and press it firmly with the putty knife. Apply a second coat of acrylic roof coat. Let it cure.

Step 4 - Patch with Sheet Metal

Cut the butyl tape and apply it to the entire perimeter. The tape will be used to seal the space between the metal patch and the roofing material, especially since the patch and the roof will be secured using screws. The tape should be at least 1 or 2 inches in width and should be taped at least 2 inches away from the hole forming the shape of the patch.

Cut the sheet metal patch large enough to cover the damage, adding at least 2 inches on every side. Place the sheet over the butyl tape. Mark the holes that you will drill. Holes should be made around the perimeter of the metal sheet and should be spaced at ½ inch away from the edges of the patch and at least 1 inch away from the other screws. Next, begin drilling holes into the patch. Secure the sheet metal screws onto the holes. Caulk around the edges of the patch and screws to prevent water from seeping into the roof. Apply acrylic roof coat all over the perimeter of the caulked patch and screws and wait for it to cure. Apply roof paint to hide the repairs.