Today, something went right (woo-hoo!). We got our attic foamed! After three (or four?) years of waiting for the right time to follow through on our plans — it’s kind of a red-letter day!
Our whole attic project actually started several years ago at one of the energy fairs in Fredericksburg, TX. A bio-based foam company, Cel-U-Insul out of New Braunfuls, gave a great presentation on how much energy one can save by insulating under the roof with spray foam insulation. We kept hearing the same thing at every presentation on green building and energy saving methods in existing homes. And when we first bought our house, our neighborhood architect and all-around great guy recommended insulating under the roof instead of between ceiling and attic floor.
Spray foam insulation is particularly effective in hot climates, like here in Central Texas. A lot of older homes have been retrofitted by installing a whole house air conditioning unit in the attic. Our central Texas summers typically see many, many days of plus 100 degree temps. The sun beats down through the roof and heats up that attic space, often to over 130 degrees. So the A/C unit operates basically in an oven, and has to work extra hard to cool things down that extra 30 or so degrees.
There are several things you can do to help reduce those high temps from penetrating your thin roof — install radiant barriers, light colored shingles or metal roofing, and/or insulating under the roof.
So we had used white shingles on our last roof replacement (just months ago) and decided to have the spray foam insulation installed, too. But first — because they usually spray over your existing gable vents, thus cutting out all light and vision to the outside world — we had windows installed where the vents had been. We also decided to put up knee-walls, shore up the roof framing a bit and improve the really large storage space up there. Then we had to have wiring for lights and plugs (some of which turned out to be unnecessary, but we didn’t find that out until several days after the wiring went in). And now that the insulation is done, we will be adding sheetrock. 🙂 I think it will actually be kind-of pretty up there, and almost feel like a room (for very, very short people only).
So, the spray foam went in today and that stuff is amazing! It gets sprayed with special equipment by experienced installers, and then immediately the foam blows up by some order of magnitude over the thickness that came out of the nozzle, filling every nook and cranny between rafters. It’s really soft and quite beautiful at this stage (I think it might harden a bit over time). The energy effiency rating is supposedly at least 50% more efficient than batt insulation. According to EnviroFoam, “Just three inches of closed cell foam can stop 95% of heat loss due to conduction, and only a quarter of an inch is needed to stop 99% of heat loss due to convection.”
We should be able to reduce our monthly utility bills by up to 60% and increase our property value 5%, just by adding the insulation. The other benefits are that it creates an air and moisture barrier, and dampens sound. It’s really very quiet up there! And, you can get a tax credit for 30% of the cost, or up to $1500 for insulating your primary residence. See more about that here: Tax Credits for Homeowners: Demilac.
You can read more about the insulation here: Insulation Alternatives and here: GreenBean Insulation.
See the finished product on our attic in the photos below — notice how the stuff really pops through every available crack; the last 5 pictures are obviously on the outside of our house.