Does anyone have experience with Roxul drainboard? I'm building a concrete Thermomass, earth bermed house, getting additional insulation over dimpled drainboard seems like a good way to go......but I was given a quote of $69 for a 4' X 6' sheet - $2.88 SF! - R 4.3 sheet (1") This seem laughably high. My contractor typically uses Epro for waterproofing a a dimpled membrane for drainage. As 18' of the house is underground, making sure the walls are protected during the backfill is very important.....Anyone with any ideas?

getting additional insulation over dimpled drainboard seems like a good way to go

Well, that's what you are paying for, then. Drainboard and additional insulation, combined.

Is there some reason you can't use dimpled drainboard and foam insulation? It would be quite a bit cheaper.

I would be putting 2" of SM on the wall then the deltaboard, making sure to seal from the SM to the wall at the top so the drainage happens outboard of the insulation. My foundation guy wants it the other way around but I really disagree with him.

I would be putting 2" of SM on the wall then the deltaboard

By "SM" are you referring to the Styrofoam brand of extruded polystyrene insulation board?

Posted By ICFHybrid on 24 May 2012 09:49 PM

I would be putting 2" of SM on the wall then the deltaboard

By "SM" are you referring to the Styrofoam brand of extruded polystyrene insulation board?

Yes, kind of like calling a tissue a Kleenex. First out of the gate usually gets that prize, eh.

Thanks for your input....Deltaboard is a Roxul equivalent it seems. I've emailed them for pricing. Just exploring different options here. I was planning to use Themomass walls but there seem to be a number of obstacles. I may just end up doing regular poured concrete and insulate from the exterior.

I just spoke to a rep from Deltaboard.... 1" = 35 cents SF. His recommendation was a waterproof membrane, dimple board and drainboard. I had called TW Perry in Baltimore and got a quote of almost $3 per SF!. I called back to say that had to be a mistake and I was assured that was the correct amount......This profession isn't always friendly to women.

Actually, I just spoke to a rep from Deltaboard and he said you want the waterproofing, the dimpled drainboard then the mineral fiber (drainboard)......

Posted By hhcjenkins on 25 May 2012 02:39 PM
Actually, I just spoke to a rep from Deltaboard and he said you want the waterproofing, the dimpled drainboard then the mineral fiber (drainboard)......

Honestly, I don't see the point of dimpled drainboard  (which is called deltaboard here, one company anyway) and a fibreboard. The Roxul fibreboard is supposed to be a way for the water to get to the weepers without the hydraulic pressure pushing it to the foundation.

Deltaboard is supposed to do the same thing so it think is better to have some foam, properly sealed, on the foundation wall, then the drainboard (which ever one you choose) can allow the water to flow freely down.