Does anyone make a green drywall?
user-2310254
| Posted in Green Products and Materials on
This question is prompted by a response I received to my question about mineralized paint. Mineralized paint is up to 95% vapor permeable. One member suggested that could be a problem if using regular drywall, which contains some VOCs, sulfur, formaldehyde, and who knows what else.
I haven’t had much luck finding a green drywall to go with the mineralized paint. Certainteed AirRenew looks like a possibility. The paperless drywalls seem to contain fewer chemicals, but I need to do more research. At one time, I was considering using MGO board, which is pretty benign if sourced from a trustworthy manufacturer.
Am I missing anything?
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Replies
Steven,
Obviously, there was a recent scandal concerning Chinese drywall. However, I have never heard any credible reports of formaldehyde or outgassing problems in U.S.-made drywall. What is the source of your information?
Hi Martin:
The comment is in my mineral paint Q&A. I don't think the poster was suggesting that standard drywall is dangerous (unless it's from China). I think he was responding to my statement on the 90% permeability characteristic of mineral based paint. That is, mineral paint makes it easier for pollutants to move through the wall. (At least, I think that was the point.)
In any case, his comments prompted me to look around a bit and now I'm wondering about the value of AirRenew, which is supposed to absorb VOCs from the air. Another interesting decision...
Steven,
Unless you have any new evidence that you haven't shared, I would answer your question -- "Does anyone make a green drywall?" --this way: U.S.-made drywall is a fairly green product. It has not been associated with any indoor air problems, to the best of my knowledge.
Martin, there are three problems with drywall. One is that it does off gas formaldehyde used in it's manufacture. The second is that if the envelope is designed so that it is permeable to the interior the drywall will also allow the formaldehyde in sheet goods such as OSB and that in FG batt insulation to migrate indoors. The third is that drywall with a permeable coating acts as a sink for VOCs off gassing in the house and can hold them for a considerable time.
I don't think that for most people these constitute a large concern, but if someone is trying to minimize the environmental hazards within a home it is an area that need bares scrutiny.
Here is one of many links to research on the subject:
http://www.healthyhouseinstitute.com/a-870-Outgassing
Malcolm,
The document you linked to makes no mention of the use of formaldehyde during the manufacture of gypsum drywall. Nor does it say that drywall contains any formaldehyde. It says that drywall can act as a "sink" for formaldehyde emitted by other materials. While the information is interesting, it does not indicate that drywall is hazardous.
It raises the question: what other materials act similarly (as a sink)? What about furniture, curtains, books, and earthen plasters? It seems that the best way to keep formaldehyde out of your house is to focus on formaldehyde-containing materials -- not "sinks."
I'm glad Malcolm raised this issue. It forced me to do further research and led me to CertainTeed AirRenew, which absorbs formadehyde and other aldehydes. I have an appointment scheduled for Monday with the local CertainTeed rep to inspect samples and ask further questions. (I always have a million questions.)
Martin:
"US EPA testing in 2009 detected formaldehyde in the core material of boards made by U.S. manufacturers. Testing by the State of California in 2003 found that both of the standard gypsum boards they sampled emitted more formaldehyde than allowed under the Section 01350 testing protocol for offices. These findings should not be a surprise to industry and the government investigators. Formaldehyde often is used in wallboard, as part of plasticizer formulations used as dispersants in gypsum slurry production. These dispersing agents are called sulfonated naphthalene-formaldehyde condensates. As the term implies, these formulations involve a combination of formaldehyde and naphthalene chemistry. (Naphthalene is an EPA-listed persistent bioaccumulative toxicant, and an OSHA-listed carcinogen.)"
Mudding compounds also contain both formaldehyde and biocides to inhibit moulds. Again I'm not at all sure how significant this is, but it is there and people can make their own informed choice as to whether they want to expose themselves to it.
Malcolm,
Your unattributed quote appears to come from a web forum posting by someone named Jim Vallette. I tracked it down; here is the link:
http://www.pharosproject.net/blog/detail/id/44/formaldehyde-additives-drywall
To his credit, Jim Vallette includes the following information:
"EPA official Jim Woolford said, 'The drywall is not a source, as far as we can determine, of the formaldehyde. Formaldehyde comes from pressed wood product, laminates and certain adhesives and other items like that.' The ever-helpful Formaldehyde Council posted a blog article that same month titled 'Drywall: Not Made with Formaldehyde-Based Resins.' The Council followed that assertion with a press statement. 'Formaldehyde is not associated with corrosion and is not a component of dry wall,' said Executive Director Betsy Natz."
Vallette's support for the claim that "US EPA testing in 2009 detected formaldehyde in the core material of boards made by U.S. manufacturers" is supported by a dead link, so there is no way of verifying his claim.
Martin,
Rather than continue a fruitless he said - she said series of links, let me concede that the materials in drywall and joint compound probably doesn't constitute a significant health risk due to off gassing and move the discussion to more useful ground.
When I took the CMHC Healthy Housing accreditation over a decade ago the emphasis was on insuring that problematic materials which might contain toxins, such as formaldehyde, were outside the conditioned building envelope. This was easy to distinguish as virtually all assemblies at the time relied on a poly air/vapour barrier on the interior.
What I think bears examining now are the effects of new assemblies that move the air barrier towards the exterior and include interior vapour-permeable materials. These strategies can move materials, such as FG batt insulation, OSB and foams, which were not designed for such an application, into a position where they are no longer separated from the interior environment.
Does this constitute a real problem? I don't know, but it coincides with a rather vigorous debate about levels of ventilation which seems increasingly to be being framed by considerations of energy use rather than potential health outcomes. These are live issues that I hope people are aware of as they make decisions about materials in their building assemblies.
The Green Building Council has an interesting article on drywall compound, which is often treated with fungicides, mildewcides, polymers, and other chemicals. It actually sounds more worrisome then plain old drywall, especially if you're doing a level 5 finish. On the plus side, there are a few low- or no-VOC options.
http://greenhomeguide.com/askapro/question/is-joint-compound-really-safe-im-concerned-about-polyvinyl-acetate-binders
So obviously mass-market industrial-scale paper-faced gypsum plus other stuff board is the ONLY wallboard solution worth discussing on Green Building Advisor. Such a relief so little discussion is had on this minor topic - and that folks keen to open discussion are shot down so quickly. Only a bazillion pounds of this stuff is installed annually across the world - because it's the perfect interior wall solution! I wonder if 100 years in the future, somebody will revisit the topic on Green Building Advisor with an open mind. Crazy talk from a crazy person, of course.