Carpet glue or insulation?

Hello all.

I've embarked on a restoration/rejuvenation project on a 16' Silverline fiberglass tri hull. My plan is to replace old and rotted carpet with a roll-on coating. There is a thick (nearly an inch) layer of foam similar to 'great stuff' brand spray-on insulation between the carpet and the gunwales. It's only on the sides of the boat, not the floor.
Is this stuff solely carpet adhesive, or does it serve some other function, such as insulation or structural support?

Thanks for any help,

Scott

 

Update:

OK, having removed too much insulation, Great Stuff in the RED can binds very well, and sands up nicely after drying for a few hours.