Hi, has anyone else had problems with on going odor with their spray foam?

We used the same product about 1 year ago and yes, I can still smell some off gassing...if that makes sense. Then again, it won't get covered for another 6 months or so so I'm hoping we won't smell it then.

Demilec makes several different types of foam. Which type are you folks referring to, open-cell ro closed cell? What specific version?

I am considering using spray foam for an application that I have, and am concerned about possible odors. Any ideas about which types of foam might have less chance of outgassing?

We used the open cell.

GreenBuildingAdvisor.com had an interesting (scary) story about spray foams with lingering odors, http://www.greenbuildingadvisor.com...oblems
and I notice that Demilec Sealection 500 open-cell foam made the horror story list several times.  However, there were also other manufacturers that made the list. 

The rim joist in my house was sprayed with a 1.5" to 2" layer of closed-cell foam (manufacturer unknown to me), and I do not notice any smell associated with it.

I have 7 to 10 inches of Demilec Soy based 2# CC foam in my cathedral roof (sheetrocked and painted) and 5 to 7 inches in my band joist (not covered) and there is no smell. When the foam was being applied you could smell it, but that didn't even last a day. My house is tight (1.4 ach50), and the only thing that off gassed so you would notice was the vinyl flooring.

Out of curiosity, I just pulled a piece of the dried Demilec foam out of a bag (I saved all the bits and pieces for a future project) and it has no odor at all (foam was applied July 2010). I have a pretty good sense of smell.

-Rosalinda

Rebooting this thread.

I am finally to the point where i will be insulating this fall.

I have settled on the Demelec Open Cell AgriBalance product and have a reputable insulator/installer who has experience and been installing for 15 years. This is a 4.45 R per inch product so I should get in excess of R23-24 (technically R 24.48) for my 2x6 walls.

I've read ad nasuem about the smell and am not concerned. The installer is seasoned, we will vent the windows for 48 hours after spraying and it will be at least 6 months before I am able to sheet rock so there should be plenty of time to allow the off gassing to subside (before we seal the walls with dry wall).

This is Trinidad Ca, about 60-70 miles south of the Oregon border, ocean front (190' above sea level on a bluff), I believe climate zone 4.

The house is built on a cement foundation with a large vented crawl space. Siding is Hardi-plank, house wrap is Dupont rain wrap (I know not as good as fir strips). Attic is vented and I will blow cellulose in the attic, once the sheet rock is installed.

1. The installer is recommending the lesser R value (Demelec Open Cell product called Seal Selection 500) under the sub floor, in the crawl space and rim joists. And only 5" of foam (floor joists are 12" deep). which will give me an appx R19 value in the floor. At first, I felt this was inadequate but after a little reading. it seems it will be fine. Anyone care to chime in on this subfloor plan? I feel the subfloor rim joists are very important too. 5" of foam there too ?

2. I am very concerned about air sealing. I know that open cell can be a great air sealer, but that depends on the installers attentiveness to the installation, right? Is there anything I should do prior to blowing in the foam to ensure proper air sealing? I know of some that have blown the inside of the walls with a latex roof mastic (prior to blowing the foam) to aide/ensure air sealing. If the technique is good, this will be unnecessary? What about around windows? Hand caulking first before blowing open cell?

Trinidad CA is indeed in Marine zone 4C:



IRC 2012 code min for between-the-joists floor-R in Marine 4C is R30, and not R19, unless you only have 2x6 floor joists, per note g in the code document.  Since you have 12" joists (are they true 12" I-joists, or 2x12s?), it's reasonable to go with the code minimums, especially in a coastal location where there will be wind washing through a vented crawlspace 24/365.

The reason the installer isn't keen on going with R30 rather than R19 is that R30 would have to be installed in two passes, whereas he can hit R19 in a single pass.  Anything more than 5.5-6" in a single pass becomes an installation quality issue, as well as a temporary fire hazard as the stuff cures.

It may be better/cheaper to air seal the subfloor with caulk, fill the joists with 12" of damp-sprayed cellulose trimmed flush with the joist edges, and install an OSB air barrier under that to support the insulation. It's a bit overkill from an R-value point of view, but not extreme overkill.

It also might be cheaper to go with an unvented crawlspace and R15 foam on the walls of the crawlspace, leaving the joist bays uninsulated.  (Any below-grade wall or concrete wall is better insulated with a couple inches of closed cell, not open cell.), with a couple of inches of EPS under the slab. (Probably too late, eh?)

Inspect the edges of where the foam meets the studs- it has to be fully filled in, without separation to air seal (obviously!).  Spraying at the wrong temp or wrong mix can cause shrinkage & adhesion issues, but for the most part air-sealing the cavities is pretty assured with open cell foam as long as the cavity is completely filled/overfilled, then trimmed flush.

Air sealing the stud bays does not air seal under the bottom plate, nor does it air seal between doubled up top plates, etc.  These are long skinny air leaks that are best dealt with when assembling the framing, but can be sealed with the appropriate caulk after the fact.

Update. We have decided on 7" of the Agribalance which will give me a R30 in the sub floor. He is pretty confident he can do 7" in one lift, although he indicated that he will probably do 2-3" on first pass, concentrating on areas where the joists attach to the sub floor to air seal and then fill up to appx 7" on a 2nd pass. This product is R 4.45 per inch, so I need 6.75" minimum to meet R30. He feels he can actually do this in one pass. This guy has been using Demilec products for a long time and is a pretty seasoned insulator. He was recommended by my Title 24 coordinator as well as several other trades. I did get a bid from another guy that was also recommended, and the 2 bids bids were similar.

My joists are I Joists (11/78" deep)...no that it matters now.

I myself will go back and caulk along the bottom of the bottom plate/sub floor seam at a later date and caulk seal the seam between the 2 top plates on both floors. And probably hand tweak any caulking that was missed around windows and doors.

I installed Carlon Vapor Tight brand electrical boxes on all outside walls and 2nd floor ceiling which are pretty cool for those who have not seen them. All can lights on the 2nd floor ceiling are double insulated cans with vapor tight gaskets. Any ceiling speakers on this floor will also have back boxes that I will seal with a spray caulk (or foam of some sort) before insulating with R38 blown cellulose.