I am buildling an ICF home which will be 1 and half story with a basement. I will have warmboard radiant heat on the main floor. I just realized that the warmboard is meant to be installed once the house is enclosed and heated, so the floor will stabilize. How can the second and third floors and roof be installed before the main floor? And then there is the heating issue. How have others done this? Thanks.

Unless I'm thinking of the wrong product Warmboard is the subfloor. It s/b installed just as any subfloor is installed(with certain caveats). If you are asking this question, something is wrong. Either I'm thinking of the wrong product, or you better study up fast!

Yes it is the warmboard. That's the issue. How can you finish the walls, put on the roof, seal the house and heat it, BEFORE installing the warmboard?

You don't! Please see the Install Guide. The Warmboard must be installed after the structural support for your floors(usually TJI's) is installed. Warmboard is your structural floor. You can't wait till later to install it.

That's what I originally thought. I've been seeing some talk about warping, cupping etc (probably before the house is sealed). I think the mention of the house being sealed and heating I've read refers to how these problems will then resolve and not be an issue. Okay, I now understand!

It might be time to contact Warmboard directly. Call 877-338-5493 and ask to speak to the project manager or Regional Sales Manager for your region.

I believe you may be confusing the instructions on applying hardwood flooring (the need to acclimate the wood in the heated space) with the application of Warmboard as the primary structural subfloor.

As the previous poster mentioned, Warmboard IS the structural subfloor and is integral to the primary framing of the home. Warmboard is based on a sturd-i-floor rated plywood and only cups/warps when exposed to extreme moisture conditions for a prolonged period of time. Sturd-i-floor rated plywood subfloor does the same thing if conditions get bad enough. Warmboard will respond just as plywood does - and it will return to its original state just as plywood does once it is dry again. Can't say that about particle board. It will swell and stay swollen even when dried out.

I've seen Warmboard rebound from some pretty dramatic exposure to moisture firsthand.

Hardwood flooring can also cup/warp when applied before it has acclimated, so the stuff you're hearing may have more to do with that than with Warmboard itself. Just follow the manufacturer's instructions for both the Warmboard and the hardwood flooring and you'll be fine.

Warmboard has been around since the late 90's with thousands of installations, so I'm sure there is ample information on the 'net beyond this humble sales person's claims.

Barry E. LaDuke
Regional Sales Manager
Pacific Northwest
Warmboard, Inc.