Jump to content

What causes this condition?

Robert Jones

Recommended Posts

Was it on a W-deck?

Is there a polyiso insulation layer below the membrane?

Does the blistering only occur at the edges of the ponding water?

How long does the water pond on the roof or when was your last rain?

Typically one of two things is going on:

1. The coating was in direct sunlight when it was applied. This causes the surface to skin off early. The trapped volatiles work their way out of the material and cause the blistering.

2. There is water trapped in the roof assembly. This usually causes a larger blister so it is less likely to manifest like the photos you have.

Link to comment
Share on other sites

Not sure about the insulation below the membrane. We haven't had a ton of rain lately and there was quite a bit of water ponding on one side of the roof. That would be the side with the blocked drains, so that was self explanatory. The blisters were located in different areas on the roof. Not just at the edge of the ponding water.

Link to comment
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now
  • Create New...