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Posted: Feb 13, 2011 12:24 PM
Where does open cell foam work well?
This forum looks empty. I hope we posted in the right place, so here goes. I just saw your ad in the new march issue of mike holmes magazine. We are from western canada, my husband is a re-modeler builder and we watch the tv show regularly. He seems to promote only closed cell foam insulation from basf?? Ok I guess, but think this may be advertising $ biased? We like mike h, but we all know he primarily promotes products and suppliers that $upport him. We would like to know the real situation.

I have heard and read great things about open cell spray foam too. Can someone tell us more about the differences of these two foams? Where, when and why to use one or the other?

We are looking to recommend foam insulation in our construction work. Thought we would try it out first in our new garage/work area we are building. Thanks.
Lynn Mether
Posted: Feb 13, 2011 04:52 PM
This is a hot button issue. Some guys tell you closed cell is junk some say open cell is junk. Guys like me will tell you they both perform great, but you have to apply them in the right curcumstances.

Open cell foam is not good for crawlspaces, basements or anywhere you could have potential moisture infiltration. It is however a very good product for walls and attics. I will not install less than 4 inches of open so a 2x4 wall I tell my customers that only closed cell because you will only get 3.5 inches of open in these cavitys. Open cell is usually the cheaper option and is why so many people use it the R-value is usually around 3.5-3.8 per inch installed.

I really like closed cell it is the cadilac of foam. It is however a little more pricey than open cell but has a higher R value per inch 6-7 depending on the closed cell foam used.

They both do an awesome job of sealing the building envelope from the outside which is where most of your heat loss goes and they also keep there R value over time and diffent temps. Fiberglass would never dream of keeping the R value over time or if there is any sort of air leakage in the home.

By the way you did post in the right spot is is just a new section just added. Congrats on being the first question posted.

Mason I'm sure will post more information.
Daniel X
Posted: Feb 14, 2011 12:34 AM
The biggest problem I have with open cell is that you through the exact same amount of prep work only to spend more time trimming excess (with closed cell I can spray within 1/2" of what I'm asked)...

Then we tell customers we're saving the planet by installing green products and we throw out bags and bags of wasted open cell foam.

Even a good open cell guy wont get his foam flat or flush with the face of a stud.
Posted: Feb 14, 2011 08:03 AM
Both have their places and even can be combined for some things. A good example is a huge house we just did, they wanted some sound deadening so we sprayed an inch on the underside of the second floor to stiffen things and then 3.5 average of open cell to help with other sounds. If we did closed cell on the entire house like he wanted at fist, then it would have been totally out of his budget and he would be using fiberglass.

Instead we did an average 5 inches open cell in his walls so we had less waste and shaving, blew the scraps in the ceiling to be covered after with blown paper and it works great.

For a general rule though, they are correct about any moisture infiltration means go closed cell. Also use it to stiffen things up if needed, when there is little room to get a good insulation and anytime they can afford it over the open cell. Otherwise, in walls above grade and attics open cell is fine as well as able to handles reducing noise from higher pitched items. Just things like the idiot playing his heavy bass music at 150db outside your house, the closed cell will help better since it is low frequency music but most daily sounds are better handles by open cell.
steven argus
Posted: Feb 14, 2011 10:17 AM
A typical job for us is open cell in the attic. Lots of square footage there. Either up under the roof deck with ignition/vapor paint or on the backside of the drywall, vented. For the walls, its any flavor of foam. 1/2#, .8#, 1# or 2#. We do not like trimming and try to avoid it. If we have to use 1/2# (open cell) we slow down and take our time. We shoot for 5 inches and have very little waste. We can make the foam look flat, not as flat as 2# (closed cell) but flat enough to keep most in the studs. We even use a combo of both 1/2# and 2# in the stud bays. Our tolerances are as follows: 2# +/- 1/4". 1/2# walls +/- 1/2" and 1/2# roof +/- 1".
Dean Nash
Posted: Feb 14, 2011 02:18 PM
If I missed someone else suggesting this, forgive the repeat.

In western Canada, I'd suspect you to be in a damp zone 4 or dryer 5 & 6 in which, I would urge caution in the use of OC foam especially if code requires a vapor barrier on the warm side of the wall.

Using CC eliminates the vapor barrier/plastic requirement which I suspect is the main reason why Holmes uses it as opposed to OC as putting plastic over top of OC foam before sheetrock would make me nervous in any climate. Furthermore, Canada has been very aggressive (my words) in assuring homeowners of a products "claims" therefore limiting thus far, the number of manufacturers that have entered the game.

Lapolla, BASF, Icynene, & Demilac (forgive me if I'm forgetting anyone) are the brands that have attained the required documentation thus far but I would guarantee that more are coming, JM-Corbond being one of them. In western Canada, I'd have to do a little research to find out who's close to you in terms of shipping but the costs to get the foam could be excessive depending on your exact location.

As mentioned in previous posts, both OC & CC perform exceptionally well when properly applied but please check with your local code enforcement to confirm what they require before choosing OC or CC and then do the research on who can get it to you most efficiently.

Good luck & thanks for the first post.
steven argus
Posted: Feb 14, 2011 04:10 PM
For some interesting articles, check out www.sprayfoam.org and www.masonknowles.com.

Also, interview a few local foam contractors and see what they recomend. Most of our business is from general contractors and when they call, we jump. We keep a good working relationship with them and they have come to trust us. Find one your comfortable with.
Posted: Feb 16, 2011 11:11 PM
Thank you everyone! This site is is great, you are all so experienced in this new product. I couldn't find much at the first site, but I searched these forums and found a lot more. It seems open cell is definitely a good product if we use it in the right places. No heavy moisture areas?? We are right on the border of BC and the states. Lots of moisture, so wondering if closed cell in the walls and ceilings of the garage is the better choice.
Posted: Feb 26, 2011 02:44 PM
With all my research I have done for my attic and crawlspace, it will be closed cell bother areas except possible the eaves area which is real tight. open cell may be used there only to seal the soffit/eaves area
John Shockney
Posted: Feb 26, 2011 06:31 PM
First I will say that closed cell is the only good choice for below grade or wet locations.

Second closed cell is always a better choice do to its higher R-value and the strength that it adds to the building.

The main reason to use open cell foam is the lower $ cost per R-value achieved and this is based on yield a drum-set of foam (1000lbs of chemical) cost about the same no matter if it is open or closed cell foam. The deference is how much foam you end up with, a set of closed cell will yield 4,000-4,500 board feet of foam or cover 4,500sqft one inch thick (R-7) where one set of open cell will yield 15,000+ board feet of foam or cover 5,000sqft 3+ inches thick (R-13) so you can get almost twice the R-value per dollar with open cell.

So if your budget allows for it use only closed cell, but if the location allows you to install enough open cell it is a much better choice than fiberglass and may fit into your budget better.

The only other reason I recommend open cell is in arias that are hard to fill or require foam to be injected like rim boards or uninsulated blind corners because closed cell could push things apart or wont expand enough to fill in around everything without the chance of leaving a void.

Hope this helps

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