Grace I&WS Blistering Problem

Good day once again everyone, just started installing Grace I&WS on half of the garage and it is blistering like crazy. Definitely air bubbles that seem to be between the membrane and the sticky stuff. Its been high 80s last few days so this thing is glued on solid now. Have you guys seen this before? If so, what was the fix? Hoping I don’t have to remove anything here… I just replaced the 2560 ft2 of sheathing… not really in the mood to rip out another 200 ft2 ;o)

I thought about trying to take to blisters out with a syringe and needle.

Thx for the help…

The roll was pretty squared up when we unrolled it. There were a lot of creases but I thought those were normal based on a few videos I had seen. We installed it in the hot sun and it was later in the afternoon that the blisters actually came out. These would show right through the shingles. SO needless to say, I am at a stand still right now.

Has to be a manufacturing issue. I’ll call ACP Applied Technologies tomorrow.

Those are not a cause for alarm. I would just shingle over as in and if I saw an area that would worry me about telegraphing through the shingles I would just nail it down with roofing nails or cap nails.


moisture trying to escape

Those are not blisters.
They are small wrinkles.
Not a defect.
Its normal.
The wrinkles do not appear big enough for there to be a problem.

I slice through with my knife any large(tall)wrinkles
In the middle from end to end.
And let it fold over itself.

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As everyone said those are wrinkles. If they’re pronounced, cut them out as you shingle. If your worried seal the cut with some roof cement.
Grace is pretty ignorant to work with sometimes.

I can’t believe you guys are suggesting slicing the Grace.

What the OP pictured is completely normal and he did a great job laying out the Grace.

I said it looked normal.
I said the wrinkles are not big enough to be a problem.
I guess you missed that.

I was speaking to other roofers about what to do if there was a tall wrinkle.

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Hi gents, I am happy to her that these are all normal. They tend to come out more once the sun comes out and the IW&S heats up. We are carrying on with the install right now. We were in the shade when we laid the two first row and everything looked good with very little wrinkles… until the sun came out. Same deal.

The wrinkles I was not happy with I stuck a needle into them and bled the air out by pressing with your thumb… no water or moisture which I did not expect since it has been bone dry out here most of the summer. The prick is so small that the I&WS just seals itself back up.

We think that either the air gets trapped as you lay it down or the air gets stucked out of the plywood as it heats up from the sun.

Grace6 !


The sticky from I+W will outgas some too when new, could have contributed.

I would never cut wrinkles in ice/water shield unless I put a patch over it. I would be comfortable with a patch facing uphill since it becomes such a gooey mess anyway, but I would definitely patch it. Slicing a wrinkle on low slope that requires ice/water shield and getting a 1/4” ‘fold over’ would not work for us.

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In retrospect, what ever efforts I put in to get rid of the biggest, more came back today… we carried on installing the I&WS today just to turn around 15 min later to see bubbles everywhere and you guys are right… just moisture trying t escape and maybe some off gasing… they kinda go away as the temperature cools off. It is what it is… even though I hate this saying. Just happy i don’t have to tore off more plywood ;o)

Thank you guys for being so responsive…

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How did this turn out? Having the same issue myself.