How do I seal a metal roof?

Without seeing it, if it is larger than 1/4”, I would advise you to buy some additional roofing, marching spray paint and overlay another piece of roofing on it, keeping in mind how house shingles are laid up (drip edge). Put it down with sealant and stainless or coated screws.

Find out who the lumber yard buys it from order direct that piece of roofing. If the local lumber yard has a display with a piece that’s suitable, then see if they’ll sell you their display. They didn’t pay for it.

If you need it bent or formed, a local metal fabrication shop will have a “break”.

If it is less than 1/4”, There are some roof tar products in a caulk tube that seal well, if the crack is small. Once again think about flashing and drip edges.

Expanding spray foam insulation might do the trick.

On my old house that has a metal roof, and I had a leak, they said it needed a tin flashing along the gable exposed edge which solved the problem. This also prevents the wind from pushing water under the roof. Make sure your roofer used the metal fastners with the gasket to prevent water from going through the roof screw holes. Any metal fabrication company would be able to make the trim after measuring your roof. A roofer installed it for me.

Thanks so much.

We had to use a rubber sealer we mopped on. There is also rubber sheets that help. Good luck!