Your metal roof is leaking. You’ve done some research and figured out that it is leaking around some of the rusted metal fasteners. This is what you need to do next to get those pesky fasteners to stop leaking water.
Karnak Karna-Flex 502 Seam Sealer is an elastomeric sealant that is designed for sealing seams of metal, concrete, spray polyurethane foam or plywood roof substrates. You can use Karnak 502 to fix the seams of your leaking metal roof. If you do, make sure you apply it with a minimum of 1/16″ thick and 6″ wide. Then apply 4″ Resat-Mat in the Seam Sealer while the 502 is still wet. When the original layer of 502 has dried apply the 2nd coating of Karnak 502 Seam Sealer.