The foundation walls at the root cellar of the Maison Grande-Digue House are constructed using LOGIX insulated concrete forms. While not a fan of rigid insulation, insulated concrete forms do have their place in the design of a foundation and in particular a root cellar. The two layers of insulation used in the ICF system provides R20 insulation for the basement plus facilitates installation of finishes both inside and outside. The concrete foundation walls also create an effective air and vapor barrier.
Being as this is a root cellar, it is necessary for a cool, damp environment to be created. The floor of the cellar therefore is an exposed earthen surface. PVC vents are installed to control the temperature and humidity of the cellar.
The ceiling framing of the root cellar must be isolated from the moisture generated in the cellar and insulated from the cooler temperatures of the cellar. The 6-mil vapor barrier is applied to the bottom flange of the floor joist, then covered with furring strips and the cellar finish.