1

all! For some reason Great Stuff offers all of their cans in Pro style, but not the Big Gap Filler. I have 3"-ish gap between a base plate and a floor joist in the basement that has very little insulation behind it. The reason is I think that the gap between that joist and the foundation wall is basically half an inch. I am guessing it was nearly impossible for the builders to wedge regular fiberglass insulation in there, or they were simply lazy. I think this would work really well insulated with foam. In fact, Big Gap Filler, with its advertised 3" expansion might be the ticket. Alas, it is not made in Pro gun style, which seems quite useful for controlling angle and thickness. Could I simply run multiple layers of the regular stuff, even if it's advertised to only expand to 1"? Am I overthinking it, and I should just liberally ugga dugga the gap filler in there?

Cheers

Zoinks
  • 139
  • 1
  • 7

1 Answers1

3

It works.

Source: I have liberally applied gap filler inside of gaps larger then it is advertised to fill.

The biggest problem I found was that it doesn't stay put if the gap is larger then it's meant to fill. 1" filler inside of a 3" hole has a tendency to roll down inside of the gap. But if you are just filling an empty cavity with the stuff it works...

That being said, great stuff doesn't have the best R-Value, and cellulose, or a close cell foam insulation would provide better insulation.

Questor
  • 1,281
  • 3
  • 8