Sunday, August 24, 2014


One of the biggest steps we are taking to be more energy efficient in the future, is to add more insulation in the home now.  The Washington State Energy code is one of the most strict in the country, but we took it to the next level. 

In our 2x6 walls, we used Blown-In-Blanket-Insulation (BIBS) - basically dense packed fiberglass. Specifically JM Climate Pro, which gets us R-23 in 2x6 walls.  This fills in behind all the electrical and plumbing. You just can't get as good of a value with regular batts.  It is a better sound insulation, too. This coupled with our 1-1/2" rigid on the exterior gives us R-30.5 on our walls. In comparison, 2x4 walls with batt insulation only achieves at best R-15.  

In our ceilings we have R-60 or better.  Neil used 1.5" of unfaced rigid insulation as a baffle to create the 2" air channel above the insulation in our vented roof.  Then BIBS in the ceiling.  In the vaulted spaces we have R-62.4. 
The pink stuff at the top plate to ceiling intersection is sill sealer...typically used to air seal and separate the bottom mudsill to the concrete stemwall.  We are using it here to create another level of airsealing at this intersection.

Below is our downstairs entry looking towards the stairwell.  To the left you can see a muddy greenish insulation which is rockwool.  This is the wall that separates the apartment from the main house and it needed a certain sound rating as well as 1 hour fire rated construction. 

We also used the rockwool in bathroom walls for added sound insulation as seen in the wall separating the upstairs guest bathroom from the hallway below.

We had a couple of tricky locations to air seal.  Two roof to wall locations that we ended up spraying 3" of closed cell foam before blowing in the BIBS.  The spray foam is about R-7 per inch. In these roofs we do not have venting.  

The installers also sprayed 1" closed cell foam at the rim joists.

Next up...drywall!