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Problems with Spray Foam Insulation (9 Posts)
Problems with Spray Foam InsulationNow that we have to get a new roof, we'll be able to finally create a non-vented attic assembly. I was all set to go with closed-cell foam, then I started doing the research. There is alot of stuff online that points to potentially serious problems. Much of it seems to come from installer error, but there seem to be a certain percentage of people with sensitivities (asthma for one example) which are exacerbated by certain chemicals in the product. I don't believe SPR has been around long enough for us to really gauge the effects.
I have started looking into safer products, like sheep's wool.
Anyone with any SPR problems or have an opinion on the wool?
This post was edited by an admin on March 22, 2012 10:41 PM.
Foam offgassingI haven't personally worked with this type of foam, but I know that urethane based foams can off-gas ammonia or "fishy" smells if they don't cure properly, or are not installed at the proper temperatures and application rates. Certain people are also sensitive to chemicals that have no effect on others, and some truly unfortunate individuals suffer from "Multiple Chemical Sensitivity" and can develop symptoms if exposed to even perfume or common cleaning chemicals.
All insulation materials have their drawbacks that are well documented. However, one that I have seen recently is an aluminum-coated "sandwich" that comes in rolls and is stapled to the rafters and wrapped around other areas. I don't know the brand name. It sort of looks like bubble wrap. I have no facts or figures about it, there was no one at the home show booth, but it might be worth investigating.
You mentioned sheep's wool, some people are allergic to that. The only other advice I can offer is that whatever insulation you choose, do your homework, and pick the most experienced, reputable contractor, and an equally reputable supplier or distributor.
Unvented attic assemblies:I just posted something on this.
Some of these hot shots are saying that with spray foam, you don't need to ventilate crawl spaces. So they spray right over all the foundation vents.
LET ME TELL YOU, IT DOESN'T WORK!!!!!!
I'm putting a second set of Tjernlund crawl space ventilation fans with adjustable humidistats and a thermostats to shut off the fans when the incoming air gets too cold.
In both cases, I had no idea that the crawl spaces had been foamed. I went into the first to service a Munchkin I had installed a few years ago. The air was creepy, and there was moisture dripping off the inverted peaks of the spray foam. Mice were living behind all the foam on the walls. All foundation vents (eight) were covered over. When I walked into the house I knew something was wrong.
The next one I saw last week. Water dripping off the foam. Vents all blocked over. All the pipes and wires in the rim joist's were sprayed over and unable to locate shut-off's. Two years ago, I had a push out on a 1/2" copper ell that was between the rim joist and the first joist. Even after cleaning it all off, I couldn't solder without exposure to the toxic fumes. There was water on all the copper pipes and it was raining under the house. I could have done a more effective job for a fraction of the cost with a fan-Tech and a humidistat. That probably voilates some stupid energy code.
Where is the peer reviewed proof that this works better than natural ventilation? I still remember all the electric heat houses that rotted from sheathing inside walls with Poly. I have houses that used Flex-Watt electric heat film in ceilings. The moisture in slant roofs dripped through the insulation and down on the connections at the bottom of the film, causing shorts and more than a few fires.
My anecdotal evidence means nothing. I have no standing in the debate. Only the well educated fools that the old timers always talked about.
What ever happened to Common Sense? It isn't a monetary value.
ThanksI appreciate your taking the time to reply Ice Sailor, to this and my other thread. The only thing I'm not in the position to know is to what extent the examples you cite followed the protocols of BuildingScience.com or other standards. Most likely they didn't, just as so many of the boiler installs we hear about on the wall never followed manufacturer's instructions or accepted standards. I know that Building Science has been testing their theories in the field for quite a few years, and of course have to modify and amend as they go along. FWIW, here is a link for some of the thinking on crawl spaces:
For the attic, with my wife having asthma, even the possibility of an adverse reaction to off-gassing of the spray foam has led me to eliminate it as an option, even if the install could be done perfectly. Removing it is murder if it came to that.
Problems:Because I am multi-talented and go into a lot of houses. I see a lot of things. I notice things long before others see them. I try to figure out why. And I end up fixing a lot of these problems. And when there is a problem, the original installer is no where to be found.
Its a real cow chip show.
Mant of these "improved" code changes are the second mistake they eb=ver made, That's if they will acknowledge it. The first time was the time they thought they were wrong, but came to find out they were right.
caution with exposed foamsWhen insulating attics be careful with exposed insulation. Most foams must be protected with drywall or similar material to reduce the flame spread rating. The flame spread rating requirement for protection is a function of the occupancy in the code.
I"m not aware of any major problems with the AireKrete system of cementitious foam but that is gravity applied so you cannot spray it up onto surfaces and have enough stick. It does exhibit excellent properties at minimum drawback. Some others may have differing views.
As for crawlspaces, they should be protected with a special membrane for that purpose professionally installed and sealed to the foundation walls. Then, this space can be ventilated and/ or dehumidified as needed. There are inexpensive monitors that can be mounted upstairs to read the Rh% in the space. Be very careful with any power ventilation equipment as it may adversely affect combustion appliances not to mention the life and durability and efficiency of the home. Always test once a system is installed to ensure performance. Blind mechanical exhausting of crawlspaces could result in a carbon monoxide exposure.
foam alternativesDid a lot of research into AirKrete a few years back and almost sprung for the equipment, but ended up going with wet-spray cellulose. AirKrete is more fireproof, bug-proof, and rot-proof than anything else out there, but it really needs to be covered up for mechanical integrity.
UpdateShould have new roof installed this week. I had looked into installing above deck polyiso rigid foam on a nailbase in addition to below deck insulation, but the cost was prohibitive for me and ROI too long.
I checked out Airkrete; guy brought over a sample. I think it's a good product but seems a bit prone to flake, it's not hard like foam. Sprayed celulose is a viable option, though it's not specifically an air barrier but will probably be OK. It gets blown in after the sheetrock is installed through holes; If you fur out from the rafters and apply sheetrock on top, then you get a thermal break from the joists.
I'm looking into a new product called Roxul batts that would fit between the joists.
I'll probably end up with around an R30, which will make the attic a far more conditioned space, but still probably a little warm in summer and a bit cooler than ideal in winter but the AC handler will work alot easier, and it should cut heat and cooling load quite a bit. I'm using an energy star white roof (certainteed silver birch) so that should do alot to offset the effects of the increased heat to the asphalt shingles caused by the insulation below.