In Part 3 of Building the BEST House possible we start installing rockwool comfortbatt 80 sub grade for our concrete slab. This Product worked even better than I could have imagined. It was super easy to handle, cut, and install nice and tight. If you have ever walked on a rigid foam insulation prior to concrete and then walk on Rockwool you would understand what I mean. Check out https://www.youtube.com/channel/UCqiKFYGBw83CDE2VthoS0Fg for a lot more info and install content if you're interested. Big thanks to Rockwool for Supporting us to Build The BEST House Possible Dan Edelman IG - https://instagram.com/danedelmanrw?igshid=YWJhMjlhZTc= Email - Dan.Edelman@rockwool.com This house plan is available for purchase and is highly detailed to help understand our building method. Https://rrplans.bigcartel.com/