The Endeavour class has completed the foundation for Canada’s Greenest Home. The crawlspace foundation is made with Durisol blocks (now called Nexcem). Durisol is an insulated concrete form (ICF) that uses waste wood chips in a cement slurry to form large blocks (in this case, 14 inches wide by 12 inches high by 24 inches long) with an integral Roxul insulation insert. These blocks create a wall with an R-28 insulation value. The main problem that we have when using this material is transporting it. Depending on the location we are going to, we have to be very cautious of the Truck Scales on route because this material tends to be quite a bit heavier than the normal concrete.
The blocks are dry stacked in running bond, and are easily cut with a regular circular saw and blade where required. A grid of rebar is placed in the blocks both horizontally and vertically, and the open channels inside the blocks are poured with concrete (in our case, with the highest slag content possible).
The Durisol system uses waste wood chips, slag content in the cement binder and the Roxul insulation is made with recycled steel slag to create the mineral wool insulation. It’s a higher impact foundation than we would typically use, but because we’re providing a conditioned crawlspace for this building, it was the best solution for this application.