Insulation, Radiant and Vapor Barriers - The REAL DIY spray foam insulation option

OK, there has to be a more economical way to do this.

I have an older house with either no insulation or very old insulation in small amounts in a space or two.

I would like to spray foam (closed cell) the ENTIRE house where ever possible.

Now after getting some quotes by professionals to come to do the job and also looking at the DIY kits that come in what look to be basically propane drums I have come to the conclusion that neither is cost effective for as large a project as I have.

Hiring a contractor would be great if I just needed a room or two done. The DIY kits are perfect for small projects or very small places. But to do my entire home using either would cost a fortune.

There has to be a way to buy the same equipment the professions use but on a smaller less industrial scale to do the job myself. That way I can just buy a large drum or so of foam and will have the equipment do the job myself for the entire house.

From what I can tell from searching the web the only two things you really need appear to be a paint sprayer machine (pump) and a proportioner machine that also heats the hose?

Can anyone help educate me to see if this is possible or chime in on what my options might be? I have a hard time believing this is that difficult a thing to accomplish but rather just rare to do.

It's a closed market. The people who sell the bulk supplies want to protect their regular accounts. And the commercial equipment, well it's probably more expensive than your entire project.

The rigid foam is half the cost per board foot. You can purchase a better dispenser to use in place of the can foam to seal and glue them in place.

If you are adding new windows and new siding, you might want to consider putting rigid on the outside under that new siding.

Good Luck

Bud

hi, i just had some sprayfoam done by professionals here in Alberta Canada. most companies charge about $3 a square foot for 2 inches and 4$ to 4.20$ for 3 inches. they claim it is r 7 per inch but i read it may settle over time closer to r 6.6. one installer said the middle stays at r so, it is best to have more. i read however that much beyond r 20 is not economical as the payback is too long. two main values in spray foam are high R value per inch and sealing that is the best and worth some extra R value, but in any case, it does not insulate the studs, which still act as thermal bridges, about only r 4-5 in my 2x4 wall. rigid over the sheeting could reduce this bridging.
if those costs are too much, as suggested elsewhere, try rigid foam, which is about r5 per inch for pink or blue, but most white stuff is r 4 and less dense. having seen pros do it, it would be hard for you to do the same job. rigid with very good taping might be pretty good. i heard of a builder that gets very good sealing with a great and very complete poly job. to that they add large amounts of blown cellulose in a thick wall to get very high R values. google "net zero house edmonton" to see details on the thick walls and insulation requiring very little heat.

rigid foam is still pricey, about 70 cents (ours, not yours, likely 55 of your cents) to get R5 and one inch, so you see how spray foam is not bad if the price includes labor and a better sealing job. cellulose is the cheapest, you can get r40 for 70 cents or less, per sq foot. i had some installers lie to me about higher than expected r value for some rigid foil faced (performs like r 22 said one with an inch -- even NASA may not have that) or blown fibreglass. watch for liers.

best of luck

I'm on the committee at my daughter's school charged with bidding-out a new building and our "green" architect has really talked-up the concept of the spray foam, but even using public money, he admits that it's pricey and probably not something that we'd actually do.

Personally, I just bought a bunch of cellulose for my attic and a lot of blue styrofoam for my crawlspace. I had wanted to do a DIY with the spray foam around my foundation walls and it's obviously the "environmental" thing to do, but the price threw me off a bit and though it'd be easier to lug the kit into my crawlspace and that could make it worth the premium, the whole thing about not stopping for more than 45 seconds and starting with the cylinders at 75° sealed the deal for me.

According to the manufacturers, it looks like the styrofoam gives you more R for the buck, but if it's the environmental concerns which are making you lean toward the spray foam, the cellulose is made from recycled newsprint, so it also can be justified as a "green" choice.

I'll be watching this thread to see if anyone can point you toward a homemade polyurethane solution, but once I did the math and took into account the downsides of the spray foam, I elected to do something else.

Good Luck.

Just purchased 4'x8' sheets blue board 2" thick, that's 64 board feet for $26 a sheet. Regular contractor supply, not a distressed outlet. That's 40 cents per bd. ft. I just pulled the invoice to double check.

As far as limiting your r-value to what is cost effective, that will change far more than the materials r-value. In the past two months, what would be considered cost effective has changed by 50%:confused:

Good luck,
Bud

DIY kits are available for the homeowner in a range of sizes. The kits 600 board foot (1 square foot 1 inch thick) and smaller are expensive and if cold will not perform well.

Temperature of the material is critical regardless of what type of product. The following refillable options (you'd rent the tanks and return them when completed) are available through DOW, Fomo Products, Polyfoam Products, Tiger Foam, etc. along with their respective suppliers.

Determine the area you wish to cover-the R-value desired and calculate what system or combination of systems you need. (example: R-value 19 @ 2000 square feet where the products r-value is 6.5) You'd need 2.9 inches of product or 5800 bft. or a system 60 (kind of heavy) 2 system 27's etc.

The kits come with safety equipment hoses, guns, tips, calibration nozzles, goggles, respirators, and the chemical. Allow time for the chemical to warm up somewhere and pick up some nitrogen tanks at your local welding supply store and you're in business. Another site to check out is of course EBay though they will have the smaller tanks predominantly.

Lastly-Going green means reducing waste! The small disposable tanks are disposed of with what inside? Go refillable to go green.

Hope that helps & good luck.

Off on a tangent here ...

I have an 1826 house, modernized (!) in the 1950s. No insulation at all in the 8x8' south kitchen wall.

Clapboards and facing on the outside; cabinets and drywall on the inside.

I want to put insulation inside the wall; I *don't* want to pull off the clapboards or drywall.

Could have sworn there would be an aerosol can that sprayed foam inside the wall, but can't find one. Tried DOW GreatStuff, but it hardly expands at all - maybe 50%, and is not recommended for inside walls.

My idea was to drill 1/4" holes every foot or so, spray the foam in slowly, letting it expand. When it reached the hole, I'd move on to the next hole.

Does anyone know of a "small job" spray foam insulation that can be used inside a wall? It's only about 60 sq feet, about 2.5" deep, so not interesting to a contractor, and not worth renting big equipment to do.

Thanks.
Tom

Nutmeg: It's not actually what you're asking about, but I did notice that the cellulose manufacturer (<A HREF="http://www.greenfiber.com/homeowners/related_products.asp">GreenFiber</A>), who supplies all of the box stores (along with their rental equipment) offers a special nozzle to insert into existing walls and bags of plugs to patch the holes, once you're done.

Perhaps sombody has a spray foam suggestion, but I thought that I'd toss the cellulose option into the air.

Good luck

Slash or anyone,

If using the DIY foam option, spraying on the back side of knee-walls, is that 45 seconds per nozzle that you have until you spray again? If you have multiple nozzles will that give you time between spraying sessions?

If I spray during the wintry cold, will the foam set?

If I keep the containers warm, is that OK?

Do I need heaters on the hose?

Many thanks...

Dave