We live in a home built in 1952, which apparently is before the concept of insulation. Last spring we tackled insulating our attic. It was probably, at best, insulated to an r-value of 5 in a couple of areas and completely devoid of insulation in most places. Now it’s probably somewhere between an r-value of 30-35 with 8-10 inches of blown in cellulose insulation. It cost us about $350 for the materials ($325) and blower rental ($20) and about 3 hours of our time one afternoon. It was a step in the right direction, but it didn’t have much of an effect in the heat this summer since the walls aren’t insulated.
One of the big projects I have slated for this winter is to finally insulate our walls. I’ve been looking into all of the different insulation methods and narrowed it down to two in particular – denim cellulose and spray foam. Both of which are (or at least can be) green, and I can do them myself. Without going into too much detail, the decision was ultimately made based on ease of installation and overall r-value. Cost was also somewhat of a factor initially, but comfort won out over cost in the end and I decided on soy foam insulation. Here are the basic comparisons base on 1200 sq ft of wall space (@ 1 inch deep):
- rvalue = 3.7 @ 1 inch deep
- installation requires at least 2 people and a hopper that can be turned off/on by the person applying the insulation
- total cost for 1000 sq linear ft = $1050 (sorry, can’t find the link at the moment)
Spray foam (soy) Thanks for the correction Jamie!
- rvalue = approx 7-8 @ 1 inch deep
- single person insulation is feasible
So for about $300 more than cellulose insulation we’ll be getting twice the rvalue per square inch. The decision was pretty easy in the end. There is one other “honorable mention” that I should point out. It is still green in the long run and a little closer in price to the cellulose insulation at about $1050 as well, although you will need to keep in mind that the foam I listed above includes shipping and 17 installation tools, while this kit does not (at least not at the time of this writing). I’m hoping to complete this project by mid-January.