Spray-on expanding foam wall insulation....

VA_Joe · Jan 15, 2006

On the cost issue - tiger foam and other stuff that I've seen on the web for DIY seem way out of line. The 600 square foot package (with one inch coverage - when fully expanded) would fill approx. 17 or 18 three and a half inch, 8 foot high, 16 inch spaced wall cavities (and no waste/excess trimmings - like that will ever happen). At $600 plus dollars that seems quite expensive when one considers that the same amount of fiberglass is only about $75. Although I don't know how much the pros are paying for the raw materials - it has to be significantly less than this for those TV claims to pan out.

This might be one case where it is cheaper to hire it out vice doing it yourself - especially if you have a large job to do like an entire house. If you have a small area to cover then these kits might make sense since it wouldn't be worth a pros time to come out to do it (or even spend time bidding on it).

Joe

db2 · Jan 15, 2006

About 15 years or so ago I hired a commercial unit to come in and do my basement (1000 sq ft) and a crawl space. I did the numbers and although it was slightly more expensive than glass insulation I decided to go ahead anyway. The entire job was completed in about an hour and a half. I initially put studs in the basement spaced 1/2 inch off the concrete so that the foam could insulate behind the studs. Foam was sprayed in the stud spaces and the up into the joist spaces. Then the drywall went on. No vapour barrier required. I would use this anywhere in a house. Worth every cent.

Hope that helps.

KAB · Jan 16, 2006

I was responding to the question </font><font color="blue" class="small">( The web sites list the foam packages capacity in "board feet". How does that give you a feel for the volume you can fill? )</font> There is a place in the calculator where you can change the thickness from 1 to ??(thickness of wall). (Then press tab to have it update.)

I totally agree that the numbers they give into relation to fiberglass are useless. Somewhere else in their information states an R value of 7 per inch.

Disclaimer: I have never used this stuff, and have no connection to the company. But I have been hearing for years that spray in foam is better albeit at a higher price.

Kurt

Ray2210 · Jan 16, 2006

I am planning on using the spray foam insulation when I insulate my shop. I will have it applied by a commercial installer. As I understand it polyurethane foam is about R7 per inch and has the added benefit of totally blocking all convection within the wall cavity. With loose fill productrs the air can circulate and heat can be convected away. It's also highly moisture resistant. It must however be covered with 1/2 inch sheet rock as it is required as a fire barrier. The stuff in itself is not a huge fire hazzard but it insulates so well that flame next to alot of it creates a heat feedback loop so to speak and temperature rapidly rises until the insulation and everything else flashes over. Around here it's not cheap at 4 to 5 times for equivelent volume compared to traditional insulation. You do get about 50% more R value per inch though and that is one of the greatest benefits. A typical 2 x 4 stud wall can be insulated to as high as R24.5. Vapor barrier is not reqired however so the material and labour for that as well as house wrap air infiltration barriers like Tyvek can be avoided. At those kind of R values cheaper 2 x 4 construction can be used and a small amount of square footage on an equal footprint in a building can be gained.

texbaylea · Jan 16, 2006

In a vertical installation, the foams are a fire hazard so must be covered. The foams also generate copious quantities of toxic fumes. The companies do their testing on a horizontal surface to get the good number.

I am still thinking about using it but the nearest commercial installer is over 75 miles away.

Vernon

Humbleto · Jan 16, 2006

Check out a product called ICYNENE. (They have a web site) It's an enviromentally friendly spray insulation that does not use all the hcfc, hfc. It is water based to spray. You will have to find a insulation contractor that uses it. Check the "green" builders and I'm sure they can point you in the direction of one. It should only cost about 25 percent more than traditional.

SPIKER · Jan 16, 2006

I saw those shows about this stuff too.

looks great, but I tried the calculator things and came up with something like 40K to do just 2 walls of the pole barn out even witht he stud/posts considering that there is a 6' plus a 1/5" which comes out to a fill depth of 7" per height X width (12' high x 50 wall is 600 sq feet times the 7" depth means a LOT of foam... /forums/images/graemlins/blush.gif

_RaT_ · Jan 17, 2006

I built a couple of homes in Maine near Camden back in 1986 that used this method. It was amazing how air tight and how little it took to heat the place. I took a bunch of pictures of it.

heehaw · Jan 17, 2006

you probably have fiberglass insulation, same as i do..and your right, it lets air in...but from what i have read, cellulose does not let the air in, and is half the cost of less, than the foam.
heehaw