Wednesday, April 30, 2014

Cavity insulation and finish work

To complete the insulation, we first sprayed a layer of closed cell foam on the basement ceiling. Closed cell is quite a bit more expensive than open cell but the basement is outside the thermal envelope of the house and the closed cell foam will provide the air barrier.  We hired a company called Green Cocoon to do the work.

The closed cell foam has a slight greenish tint to it.  I only had a single layer (about 2") applied to save on cost.

After installing the foam, we added batts of Roxul mineral wool for a big boost to the R-value at a relatively low cost.  The Roxul also provides fire resistance, which otherwise would have had to be provided by spraying a fire resistant coating onto the closed cell foam.  The coating actually costs way more than the Roxul but provides no additional insulation.

Upstairs we sprayed in open-cell foam since we weren't depending on the foam as an air barrier.

In the picture below you can see that they do every other cavity, to make it easier to trim the overflow.

Prestained knotty pine arrives from Duragroove.  Two palettes remain in the picture below but there was a third one when we started.  The boards are all 16 feet long and since I couldn't find my extended fork lift we had to unload it all by hand.

And here's what it looks like installed.

In the picture below you can see the indoor unit for the heating/AC system.  That one unit is supposed to be able to heat the entire house.  Above it you can see the vent from which fresh air will come into the house. Since that air will be colder (in the winter) than the air in the house, putting the vent above the heating unit will hopefully temper any cool breeze from the fresh air vent.