Applied on top of asphalt shingles, it worked great to stop a severe leak coming through mushy spot that had been leaking for sometime through OSB sheet under shingles. It's a real mess to apply from the can, be sure to wear gloves, I wore nitrile gloves, and work clothes you can throw out.

How long does leak stopper last?

So how long can you expect them to last? It depends. If the leak is mild to moderate, we've had customers run 10,000-50,000 miles with no further issues. If the leak is more severe, or on the edge of becoming severe, the repair might last a shorter duration.

Is leak stopper the same as Flex Seal?

Flex Seal and Leak Seal seem to be pretty different when it comes to curing time. As Flex Seal Products writes, the liquid sealant fully dries completely in 24-48 hours and cures fully in 48 hours. ... As for Leak Seal, both the spray and brush sealant dry to the touch and can be recoated in 20-30 minutes.