July 20, 2009

Energy efficiency starts from the outside in. On the outside of the foundation walls we installed 2" R-10 foam two feet down from the top of our foundation. Studies have shown that exposed concrete will heat up and wick up moisture when exposed to the sun. With the 2" R-10 foam on the exterior of the foundation this will stop the concrete from heating up and sucking up that moisture. It will also help us in areas where the sun is not exposed to the concrete to keep it a more consistant tempature.

Under the 2" R-10 foam we installed a product call Tuff-n-Dry. This product is applied over a tar coating that is sprayed onto the concrete and footing. The Tuff-n-Dry product has a R-Value of 5 per inch, and we installed 2" of the Tuff-n-Dry product for a total of R-10. This product acts as a drainage board against our foundation by allowing the water to pass through the product to the drain tile located on the outside of the footing. The other great feature of this product is that it gives us a 30 year dry basement warranty.

It is very important in our net zero home that no moisture enters through our building envelope whether it be through the 2x6 wall or a 8" concrete wall.