Insulating the Gaps

I started to insulate the joist gaps between the floors (from the basement). First up was the wall in the laundry room that neighbors the garage. I went to visit my best friend (Home Depot) and bought a 2" thick 4' x 8' Rigid Foam Insulation board. My friend was nice enough to cut it into 2' sections so I could fit it in my car. I measured the space to fit in the joist space and rough fit them first, then I used some construction adhesive (safe for foam board) to stick the boards in place. I made sure to leave a little gap all the way around for the spray foam to fill.

Space before foam...

And after, glued in place.

The insulation, as you can see, has an R-10 value - so it's a decent amount of protection from the elements. The Owens Corning stuff has the best rating too for 2" - although the DOW stuff at Lowe's has the same R value, for some reason it's almost double the price. If I wanted to go overboard, I could add a double layer in too, but that's probably overkill for the particular application.

So, using about 2 cans of "great stuff" expandable foam, all the cracks around the insulation are sealed, and also the gaps between the foundation wall and the sill plate.

Helpful tip. Don't be dumb like me - wear gloves.

All done. Should keep those ants and anything else out, too (including air).