I wanted to share with everyone an article written by my Energy Consultant, Laura Paprocki, from Trinity Environmental. She is an important partner in the construction of all of my homes. Please enjoy it, I hope she will contribute more in the future.
This article focuses on a green practice; green materials can only function properly if the correct installation practice is used. One agreeable aspect of how to achieve green construction is the overall “tightness” of the building shell. This is also known as “air sealing”. Why is this so important? Fewer random air exchanges equate to higher efficiency, and this does not have to add lots of cost. Because of the fact that warm air rises, the most effective place to air seal is the attic. There are 2 ways to approach attic air sealing: 1) Include an “attic air sealing” package in your bid to the insulator. An attic air sealing package, when done by a contractor usually consists of applying a 2 part closed cell foam over all interior and exterior top plates, along with any other penetration up into the attic. This then creates an air tight “lid” on the home. 2) Get up in the attic armed with caulk and Great Stuff and be able to recognize the areas that need air sealing, and get er’ done! Talk with your building science consultant if you have questions.
While warm air rises and escapes up top, cold air sneaks in down low. Thus the next most susceptible area for leakage is the sill box or rim joist, in a two story home the band joist is also vulnerable. This again can be approached in 2 ways: 1) Spray foam the rim and band joists with a 2 part closed cell foam, being sure that along the rim joist the foam is brought down low enough to cover the connection between the mudsill and the top of the foundation wall. 2) Have your framer use a thick caulk, or construction adhesive under the mudsill in place of the sill sealer or use a flexible caulk and/or Great Stuff to seal all the areas as show below and along the band joist as well. Please note that there may be a situation where after the sill box is spray foamed a contractor has to put a penetration through it. Once all work has been done on the home, a final review of the sill box should be done.
If you are currently wondering how your buildings compare when it comes to air tightness, partner with a Focus on Energy Consultant who can perform blower door testing on your homes and better pin point areas of leakage and ways to improve on the overall tightness of the home. The Green Built Home program awards points for different levels of home” tightness” and proper air sealing practices.