I have a number of galvanized steel granaries on my farm. They have roof vents cut into the sloped roofs. When it rains, water leaks into the granary and causes the grain to spoil. The vents were originally bolted to the roof with a sealant between the join. I have applied caulking to the joins as well. They still leak. Can you recommend a product that could be applied to join between the roof and the vent that would stand up to the extreme temperature variations during the year.
Answer:
You'll have to read more carefully what is on the caulking tube that you buy. There are products available that will stand up to both the moisture and the temperature variations you have to deal with. Your vents may also need to have the caps lowered so things can't blow in underneath the cap and have access to the screen that keeps bees, etc. out.
