What can one expect to pay for closed cell insulation in the NY area? I know it is usually calculated by the board ft if anyone has a range. Also, what is the difference in R value between closed cell and open cell. Are there any advantages of open cell vs closed cell other than the price. Thanks

Your question is very difficult so i don't answer you if you wait me i will search from the search engine and i will gave you answer after one day.

I did some research on spray foam. It just seems that you never get a straight answer from the contractors. I guess when the structure is in place and a physical estimate can be made then I can get a true price. I was just hoping to get a range in price on board feet so I would have some idea. Is this going to cost me $5k or 25K.......

Not sure about the New York market, but most guys are charging around $.90-$1.10 a bd ft for CC and around $.35-$.40 bd ft for OC in my area. OC does a little better job of sound absorbstion, but other than that, as long as price isn't an issue, CC is the way to go. At 2" you get an approved vapor barrier. If I were building a house for myself I'd go with 3" of CC in the walls. Attics are a good place for OC because you get so much in there for a lot less $$ than CC. Another option would be 3" of CC in the attic then blow the rest with fiberglasss just to appease the code guys. Hope this helps! What size of house are you building?

Foamer, Thanks for the info on prices. I just got a price for cc at $1.00 a bd ft. So I guess that is right in line. Of course there is always a budget. I am looking to build a 1900 sq ft house with one bedroom on the first floor. I am looking at using the basement for the other bedrooms so when the kids are gone I only will utilize the first floor. The one other factor to mention is that the ceilings on the first floor will be 10 feet. I need to build to energy star standards as my town requires an energy star evaluation to obtain a building permit. I was just trying to figure out an approximate cost of insulating this house. On the first floor alone there is approximately 9000 bd ft in the wall alone.

In MA these days 2lb density closed cell is about a buck a board foot for larger jobs, open cell is about 40 cents. Typical closed cell R is R6-6.5/inch, open cell R3.4-3.6/inch for half-pound, a bit more for 0.7lb Demilec.

There are advantages and disadvantages to either, depending on where the goods live in the assembly, and what the other elements of the assembly are. Open cell foam (half pound density) is fairly vapor permeable, which is great when you need to set up the assembly to dry, but not so great in situations where you need to block or slow moisture. Closed cell foam is typically 1.2 perms at 1", and going more 2" (~0.6 perms) makes it fairly vapor retardent. At even 3" of most cc foam is slightly more vapor retardent than the asphalt kraft-paper backings on batt insulation.

Closed cell foam at 3" or more also becomes structural- it can effectively glue roof decking to the trusses and provide racking-rigidity to studwall assemblies, etc.. But that rigidity can sometimes be a problem for overall dimensional stability over time in applications where it might need to flex. Open cell is far more flexible.

Closed cell is more than twice the weight per unit R as open cell to, which can sometimes come to play when calculating loading factors (but rarely if ever, in residential apps.)

Either can be used as an air-barrier if applied with care, but neither is guaranteed to be an air-barrier in a less-than-meticulous application.

So the questions are, where in the assembly do you intend to use spray foam, and what are your thermal & moisture control needs/goals?

Unlike Foamer94, rather than 3" of cc foam in the cavities if I were building a house I'd go for 1-2" on the exterior of the structural sheathing and fill the cavities with wet-sprayed cellulose or dry-fiber blown-in-netting for about the same money (or less) than 3" of cc in the cavities. The ~R4 thermal bridging of the studs robs the thermal performance of the higher-R foam- an open-cell cavity fill (or celluose) delivers about R10 for a whole-wall R value when the thermal bridging is factored in, but going with 3" of closed cell between the studs only brings that up to R12-ish. But 2" applied to the exterior adds the full R12, since it isn't being short circuited by the studs, so wiith a cheap-fiber fill you end up at R22 for about the same money as R12. What's more, applied to the exterior the air-sealing of the foam is much more assured, and it's easier to apply, it forms a weather resistant barrier (it's waterproof) and with ~50% of the R on the outside of all structural wood there is no need for an interior vapor barrier (anywhere in the US lower 48 ), a win-win-win-win situation.

With 2x4 construction even 1" of exterior cc foam has sufficient R to be able to use cheap fiber with no interior vapor barrier in a NY climate, and you'd end up with ~R16 for a whole-wall R rather than an ~R10 wall using just an open-cell cavity fill. See: http://www.buildingscience.com/documents/guides-and-manuals/irc-faqs/irc-faq-insulating-sheathing-vapor-retarder-requirements It's less money than an open cell full-fill and deliver 60% more R-value, plus better air sealing. The foam budget is usually better spent on the exterior than inside of stud or rafter bays.

Attics usually have more space so R/inch is much less of an issue. A 1" shot of cc foam as an air-seal & vapor retarder plus a foot of cellulose (which performs better at the temperature extremes than standard density fiberglass) delivers far more performance than 3" of cc foam + fiberglass up to code-min, for less than the cost of just the 3" of closed cell foam. With good air-sealing technique on the attic floor/ceiling, if structurally factored in for the load of even deeper cellulose, 15" of cellulose would be cheaper still, and perform as-well or better. (At 15" settled depth figure on ~2lbs square foot static loading, in which case 5/8" gypsum on 24" truss spans isn't gonna cut it- it'll bow, and truss chord loading has to be looked at.)

If insulating the roof deck rather than the attic floor, then 1-2" of closed cell makes sense, with the rest of the interior R being cheaper fiber. See: http://www.buildingscience.com/documents/reports/rr-1001-moisture-safe-unvented-wood-roof-systems

Dana,
Thanks that does clarify some issues for me. How about basement walls. What would you recommend?

Good points Dana...actually if I were building a house for myself I'd go with staggered 2x4's, spray at least 3" everywhere, wrapping the exterior studs, eliminating thermal bridging. Not really sure how you can say "the air-sealing of the foam is much more assured"?? Unless of course you hire an inexperienced or careless installer. I would think any seamless system would be a much better choice. As far as the 1" of CC in the attic goes, don't expect to find a quality contractor that going to do that for anywhere near $1.00 bd ft.

Foamer,
From an installer point. How many bd ft of cc do they get out of the two part 55 gal drum of material?

Foamer 94: When you foam the cavity bays, you're only sealing the stud plates to the sheathing at the interior of the stud bay. Even when done perfectly there are leakage paths under the bottom plate and above the top plate. When you foam the exterior of the sheathing you're sealing every seam on the sheathing on the outside of all plates, sills & band joists. On the exterior the odds of missing a corner here & there are zero, whereas in awkward interior applications there are situations where you can't get the right angle on the gun so you shoot & pray, hope for the best. If you've never done blower door testing on a foamed-bay home with thermal imaging or smoke-tests to find the leaks prior to putting up the gypsum, you'll probably be surprised at the results when you do.

On the 1" flash minimalist approach to attics or walls, it's less volume and will cost more per board-foot given that it's a smaller job, but the overall cost per unit-R is much reduced which allows for a higher overall-R and the air-sealing quality is the same as if you'd done 2-3". In stud-bays and roof deck 1" is sufficient to protect the roof deck or sheathing wood from wintertime moisture accumulation from interior moisture, whereas with open cell it can't, and MUST be vented in a NY climate.

The staggered stud 3" foam approach is an expensive way to get an R24-ish wall, and it does nothing to break the thermal bridging at the subfloor, band joist, and foundation sill. You could spray the interior of the band joist and foundation sill, but that would still leave the bridging at the top & bottom plates and at the sub-floor, the window & door framing, etc. With 1.5" of exterior closed cell on standard 2x6 framing with wet spray cellulose cavity fill would deliver better performance due to more complete thermal breaks on the framing for about half the foam, (with 25-30% lower total insulation cost- cellulose isn't free, only cheap), as well as lower framing costs and an inch thinner on overall wall assembly. "All foam or go home!" isn't exactly the most cost effective answer to every insulation stackup, and with closed-cell foam that's even more so. At ~17cents/R/square-foot it's about the most expensive option there is. Used judiciously & well it's great stuff, but it's not the only way to get there.

peteinny: Basements are a special case, since you need to allow some drying of the concrete toward the interior unless you were religious about putting a capillary break between the footing and poured wall, as well as between the slab and poured wall, and between the concrete & foundtation sill. If these steps aren't taken even 2" of ccSPF may raise the moisture content of the wall to the point that it rots the foundation sill, or causes freeze/thaw spalling and efflorescence on the above-grade exterior portion. In new construction insulated concrete forms (ICF) are a better option, with a 1-2" shot of ccSPF sealing the foundation & band joist to the interior EPS of the ICF. If you don't know just how much you have in the way of capillary breaks or ground moisture, insulating the interior with 2-3" rigid EPS (bead board, unfaced) + interior studwall with unfaced batts (and a capillary break such as poly sheet or sill gasket under the bottom plate of the wall), with unfaced fiberglass or rock wool batting to round it out works in a NY climate.

Alternatively you can set up a 2x4 studwall 2" from the concrete an do an all open-cell fill (but it's more money), and doing the foundation sill & band joist with closed cell is also still necessary. With stud bridging factored in that would end up at ~ R17. With the rigid EPS approach you R8-R12 of EPS outside the stud edge, and a whole-wall R of R18-R22, depending on stud spacing and batt density. Done on the cheap like that there's some rationale for ~R20 foundation walls in a NY climate, but with an all spray-foam approach R12. Concrete walls are pretty good air-barriers, so you're not getting much "other than R" benefit with an all spray foam approach there, but at the band joist & foundation sill ccSPF is still your best option. Virgin low-density EPS is pretty cheap, typically 10 cents per/R/square-foot, but open cell foam can be comparable. Where you can get it (Insulationdepot.com or local commercial roofing contractors who handle it) reclaimed/recycled EPS from commercial flat-roof demolition or re-roofing is more like 3-4 cents per square foot per R, so unless you have the highest labor rates in the world it's going to be cheaper than an all ocSPF approach. (I did my own basement as a retrofit, using reclaimed 3" fiber faced R18-R19 roofing iso at ~3.5cents/R/square foot. Be careful if using iso- not all facers are sufficiently permeable.) If you can get 3-3.5" reclaimed roofing EPS, it can be fastened to the wall with 1x furring through-screwed to the foundation with tapcons, mastic-sealing the seams, or trapped in place with a studwall with or without batts. The permeability limits for using low-density EPS are around 4", or R15-R16- going thicker will result in the same moisture issues as 2"+ of closed cell foam. R8-R10 EPS + studwall is safer, when the capillary break conditions are unknowns.

Sorry Dana, I misunderstood what you were saying at first. Anyway, I agree completely that foam isn't the end all be all. There are many ways to get a great wall. Beings that I have access to a spray rig and the ability to do it myself, my cost per R is going to quite a bit lower I'm by no means a technical expert in building assemblies so I appreciate your insight. Off topic a bit, but what are your thoughts of fluid applied house wraps like the one Prosoco makes?

And peteinny, we normally average around 4,000 bd ft for a set of CC. There are others out there like Corbond/JM that say they are getting over 5,000 a set, but naturally it costs more so I don't know what kind of difference it would make in the price. I know a lot of manufactures are working on new blowing agents, so hopefully we'll someday see the price of foam come down, at least on the suppliers side

Great information. Thanks .

I'm not familiar with ...fluid applied house wraps..." got any web-available info/data/specs on 'em?

Dana1, Here are a few of the spray on air barriers: Enviro-Dri spray on house wrap by Tremco http://www.tremcobarriersolutions.com/products/enviroDri.asp and Perm-A-Barrier by Grace Construction Products & Air Bloc 31 by Henry Co. & Prosoco R-Guard.

Thanx!

How do you spray the exterior of a house and get a uniform flat surface to apply siding on top?   I can't get my head around that.

Posted By NFC on 19 Aug 2011 01:22 PM
How do you spray the exterior of a house and get a uniform flat surface to apply siding on top?   I can't get my head around that.

You don't- you pre-apply 1x2 or 1x3 furring on spacers cut from rigid XPS, through screwed to the studs.  The furring then serves as a depth-gauge for the foam installer as well.  The 1x furring also creates a rainscreen gap/cavity, maxing out the drying capacity of both the wall assembly and the siding.

If the exterior foam is more than about 2" the benefit of the rainscreen to the structural wall is negligible, but it's significant at lesser thickness.  At a flash coat nominal  1"  most 2lb foam is in the ~1.2 perm range, and the drying enhancement provided by a rainscreen is significant.

In stucco siding the flatness is determined by the anchors for the lath, and again, a rainscreen gap is a huge boon to the moisture control, given the massive quantities of moisture that stucco can retain.

I paid for 7” inches (R-50) of 2 pound closed cell Soy based foam on 842 sq ft of roof substrate @ $5.20 per square foot. The foam was actually 7 to 10 inches once applied. Because we did all the plastic prep work and clean up, the contractor sprayed our 153 linear feet of 10 inch wide band joist (and a few other bits and pieces) with 3 plus inches of foam at no additional charge.

Total price - $4,378.40 for the foam, plus we gave the guy who sprayed the foam a $40 tip, and spent $50 on the plastic, which we later used as tarps when we painted, and for wherever we needed to seal off a room or area for sheetrocking etc. We are located in the Finger Lakes of NY.

-Rosalinda

Rosalinda,
Thanks for the info. Sounds like you got a very good price. I'm only a few hours from your area. Do you have the info on the guy who did the foam?
Thanks again,
Pete