Both HD and Lowes sells PL, and they make PL300 Foamboard adhesive. I used it with the Dow blueboard and it works great. Inexpensive, too.

Thanks much.

I forgot to ask if and how you braced the board to the concrete or did you fasten it down mechanically right away?

The Dow blueboard is tongue and groove. I cut it for a snug fit top-to-bottom, so I only glued a couple spots of each sheet to the wall, and then glued along the entire edge of each one. I put up all the foam board first and then put in the furring strips. Have yet to sheetrock over it…

Thanks very much again.

Good luck with your project - you’ll be glad you did it!

I couldn’t find the BIG tubes of PL300, only the dainty ones. If that matters to you.

HD had some big tubes of the polyurethane.

THE most important place to insulate is the sill plate, however to do it correctly (i.e. no air leaks) is to use the spray foam, and for the amount of space it is cost prohibitive for the homeowner to use cans.  It is best done by a professional.  There is so much air infiltration and loss through your sill plates that it is actually more important to insulate that area before even adding any to your attic.

sinnian - 07 August 2008 11:34 AM

THE most important place to insulate is the sill plate, however to do it correctly (i.e. no air leaks) is to use the spray foam, and for the amount of space it is cost prohibitive for the homeowner to use cans.  It is best done by a professional.  There is so much are infiltration and loss through your sill plates that it is actually more important to insulate that area before even adding any to your attic.

just bought a can of truck bed liner spray from wal mart & leaked as it malfunctioned but after it dried on the can, the stuff looks GREAT for a plastic, spray finish to block air infiltration. $7/can

Well, I got some furring strips to go along with the 10 Foamular tongue in groove 2” boards.
Found a big tube of the pl300.  Also, harder to find were 4” tap cons which I figure is the size I need.
I’m still not clear on how to glue/seal the foam to the wall as well as seal to each other.
The http://www.buildingscience.com website is not that clear.
Would there be a bead all around the edges of each piece of foam to glue and seal to the concrete, plus some in the field?
Then also some glue on the tongue in grove section for sealing?
That’s a lot of glue.....

Don’t over-think it; the glue just keeps the boards in place until you get the furring strips in. Then if you want, you can seal along the perimeter to kill any chance of air currents setting up. But I think even that is a pretty subtle detail compared to the benefits of just getting the insulation up.

Thanks.  They’re pretty seal crazy on that website, but the Dow site (Corning has nothing specific) just seems to say to slap it up there with furring strips.

I agree with precaud. In our (tall) crawlspace I just used Liquid Nails LNP-901 heavy duty glue (approved for foamboard). Bought a case of the large tubes at HD and put a generous amount on each sheet. (I think we got about 2.5 - 4x8 sheets per large tube). Let it fire off for a minute, then pressed in place. Wedged a couple 2x4 T sticks to hold it for about 5 minutes while we got the next one prepped. That’s all, no tap cons, no furring strips. It’s been up for 3 years now and is very solid. That stuff is not coming down.

Does it work? The coldest temp we’ve seen in the crawlspace was 60, with it 20 degrees outside. Normally in winter it sits at about 63 degrees.

Yeah, I don’t want to overthink it.  But, it’s not that clear to me how to brace it when applied on the interior.  I’m thinking I’ll use the furring strips - don’t know about the time factor.  Again, not overthinking: key.