Metal roof sealant prevents fastener blackout and stop major causes of metal roof leaks. It stops and seals movement from screws reducing replacement of fasteners. Good roof sealant will last a long time and stays flexible. It also prevents UV deterioration of washers and fasteners. You can use it to seal your new roof just before applying elastomeric coating. That way you can be sure that your metal roof will last for many years.
Metal roof leaks are often caused by fasteners getting loose due to heat. Temperature change causes the metal roof panels to contract and expand making holes wide and fasteners loose. Leaks from metal roofs can sometimes be hard to locate when moisture travel along the edge and leaks appear very far from the damage.
Read the instructions on your metal roof sealant and follow the manufacturers suggestion on thickness levels and coverage.