How to Repair a Leaky Metal Barn Roof

On a leaky metal roof, water never travels in a straight line. Metal roofs are notorious for that. Water follows trusses, seeps down sidewalls or pools up waiting for a chance to escape. In order to repair a metal roof, check flashing around vents, pipes, sky lights, J-rails and rusted or worn-looking areas.

Things You'll Need

• Galvanized metal
• Sheet metal screws
• Butyl tape
• Caulk
• Caulking gun
• Flexible putty knife
• Tin snips
• Wire brush
• Safety glasses
• Work gloves

Instructions

1. Inspect the entire roof for possible leaks. Check all seams, seals and flashing.

2. Scrape off any flaking or loose areas carefully with a flexible putty knife. Remove all dirt from the area you need to patch.

3. Apply a 1 or 2 inch strip of Butyl tape around the perimeter you need to patch. Cut a piece of metal to overlap the hole by 2 or 3 inches. Place the Butyl tape on.

4. Drill holes through the metal patch and metal roof, placing them 2 inches apart. Screw metal screws through patch and roof. If the patch is still loose, add metal screws 1 inch apart.

5. Seal the repaired part of the roof with caulking. When the caulk is dry, cover it with roof coating.

Tips & Warnings

• Before climbing on a metal roof, inspect the roof and trusses to ensure they can hold your weight.

• Place a 1/2 inch-by-2 feet wide-by 4 feet long-board along the trusses to walk on. Walk on the board to prevent splitting seams on the metal roof.

• Do not add any more rumble buttons. Rumble buttons are 50 cent-sized metal washers with neopreme metal disks under them, drilled for a screw that pulls the roof tight.

• Do not screw the roof to the rafters.

• Never walk on the metal roof. Only put your weight on trusses (rafters) or use the board.

Resources

• Repair a metal roof with Ames Research products.