July 21, 2009

Under the concrete slab in the lower level we stepped it up another notch. We installed 6 Mill plastic with all the seems taped to act as a moisture barrier between our 4" of gravel and lower level concrete slab. This barrier will perform two things for us as a moisture barrier and a vapor seal for our radon gas. This will force all radon gas and moisture to the drain tile and not through the lower level slab.

To ensure that the net zero home was insulated on all six sides we installed 2" R-10 foam on top of the plastic. We taped all seams and we put Great Stuff expandable foam around all penetrations. We also install 1/2" R-5 foam on all the footings and up the wall. This 1/2" foam acted as our thermal break between the foundation wall and lower level slab.