Plaster walls and asbestos content
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Anonymous
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I wanted to share my experience over the past 2 weeks with working with plaster walls in my house, having now lived there 13 years and never thought of this before, yet still having done several small various projects.
Old plaster walls can contain asbestos fibers. Old drywall can contain asbestos fibers, as can old drywall joint compound. Its not advertised, even on EPA's asbestos website. Discussions online are unhelpful for definitive research. 2 builders I spoke to, 30 years experience, it was news to them. After cutting out 4 sections of wall, 16" wide each, with a sawzall (and actually generating very little dust due to very good vacuum/venting setup), I inexplicably started wondering what the composition of the wall material was as far as possible asbestos. It is rock-lathe plaster; 3 layers. A "drywall" layer that is paper-covered gypsum board, a brown coat of plaster, then a 1/8" pure white veneer coating of plaster. You DO NOT need a "test kit" from a place like Home Depot. Those things are just a bag and gloves. You still need to pay the lab, you still need to pay the shipping! All labs have instructions and forms online, use a little Ziploc bag. And the good ones turn it around in 1 day and not a week. Took samples of each layer, and sent to "Western Analytical Lab" out near Los Angeles. $30 for the first sample, $20 per additional. Overnight shipping was $20. They had my results emailed to me by the end of the next day after I put them in the mail. Mailed Monday, results Tuesday night! ACM, a local remediation outfit, says they usually see asbestos in the outer veneer layer. But my lab results showed both plaster layers were clear. The bottom drywall layer, though, tested positive for "trace" amounts of Chrysotile asbestos. Less than 1%. At that level they do not measure more accurately unless you do a point count ($80 test) but the lab guy (who answers ALL your questions, he's great) said there's no real difference between say 0.2 and 0.4%. Anything less than 1% is not legally and technically called "Asbestos Containing Material" BUT you should still use very good dust control practices when working with it. Keep it wetted down and HEPA vac the dust. The lab told me its rare they see it in that lathe layer. This is not a Big deal, but something to be aware of. You never know what is where in your home, it is not like it will jump out and bite you but if you are going to do work...spend a few bucks for tests. As a further note, Chrysotile asbestos (white asbestos) is the serpentine type, and is NOT the type connected to the rare disease mesothelioma (see every other mid-day cable TV lawyer ad). While the law and OSHA classifies asbestos as one thing, Chrysotile is a very different mineral from the amphibole asbestos used in pipe insulation and other thing. (Sometimes Chrysotile asbestos in mines has been adulterated with amphiboles, but end-user products are a different situation.) Chrysotile has a very short bio-persistence, days in fact. Amphiboles go in you and just...kind of...stay...there. Ew. Chrysotile IS connected to asbestosis and lung cancer. But asbestosis is lung scarring from very high concentrations for long periods, and lung cancers from this require also being a smoker. Its like the two combine in some unholy alliance. But all silica dust is worth keeping out of your lungs. As a side note, don't ever mess around with the white-wrapped pipe insulation type asbestos if you find it. Don’t mess with it. If in doubt, test. Wet it properly for taking a sample if absolutely necessary. Then call the pros. One of the horrible things about amphiboles is that people who work a day or two unprotected and get a heavy dose of that stuff have gone 30-40 years and then gotten mesothelioma. A short, sharp dose of amphiboles is enough to put a hurt on you in a few decades. (And yet everyone is different....you're 11x more likely to die in a car crash than from that disease.) A friend of my dad's (from years ago) died of lung cancer last year. He was a former smoker, but quit in the past. But he was also a builder. Always working with wood dust, stone dust, etc. Especially woods like cedar and redwood. Not protecting your lungs from things like that, over years, can overwhelm your body's immune system and ability to fight off DNA mutations. If you're doing dusty work, get yourself a mouth-nose respirator mask with HEPA cartridges and wear that, don’t bother with the cheapo white dust masks, they don’t do crap. Spend a few dollars to keep your lungs clean and healthy. Gosh knows we all have enough in the air any given day to knock us on our backsides! |
Anonymous
| Thanks, OP. This is very helpful. How old is your house? Do you know if there are certain decades where you are more likely to find asbestos in plaster? |
Anonymous
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op here. Mine is 1947. You won't find asbestos prior to 1900, or after 1978* in plasters. Many plasters have fibers in them, usually horsehair, pig hair, jute, hemp, etc. But sometimes asbestos fibers were added on site, by a plasterer, depending on what they were trying to do or the location, etc. It wasn't in the plaster itself, but was added on-site. Except in the case of that backer board, where it was in there from the factory (in trace amounts).
*(while production was kind of banned then, nothing says the material still wasn't around and could be put into things) As great as it would be to use dates to be sure of things, one thing I have learned is that the ONLY way to know truly is to do testing. |
Anonymous
| let me correct myself...even late in the 19th century...still do a test. Nothing is magic about 1900 in fact. Just less likely earlier or later. But later, there was about zero plastering done and all was drywall. |
Anonymous
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Really informative post. I read and never new 80% of what you said. Like gypsum covered drywall was used in 1947 etc.
Are you working on a project? How are you going to handle containment/vacuum even though 0.2%. Your approach to date has been very deliberate. Thanks for the education. Knowledge is power. |
Anonymous
| Tear it down and build new |
Anonymous
| Ok, thanks for sharing. We tested our house and it wasn't the plaster - it was the first layer of paint/primer that had the asbestos in it. A one time exposure is ok (its an issue for kids more than adults), its ongoing frequent exposure that is the problem. Or, we'd be dead between the asbestos and lead in our house. |
Anonymous
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op again.
Are you working on a project? How are you going to handle containment/vacuum even though 0.2%. Your approach to date has been very deliberate. Yeah, over the years I have done lots of little cutting type projects. I'd figured out that putting a vacuum pickup right below the sawzall caught about 95+% of the dust. So much that even in the room you'd find very little settle out onto surfaces. The issue comes with...what's going THROUGH the vacuum. If its not a HEPA, particles just can go through the filter and back into the air! For the wall project I just did and the few cuts I did in late 2013, I had ported the vacuum output out a window. I had no idea at the time, but that was a really good thing to do. All this cutting was before I thought to test. And why should I think to test....nobody really mentions it. And of course I had no idea when we ripped out ALL of our guest room walls. BUT the contractor who did that (not me) had a negative air machine running which sequestered all that dust in there and kept the room negative-pressured). That dude didn't even wear a dust mask and was ripping out walls for 3 days! How are you going to handle containment/vacuum even though 0.2%. For drilling holes from now on, like for picture frames, just going to drill through a wet paper towel. No more cutting. I'm designing another bedroom to add on, and that will require a lot of plaster demo in an adjoining room....I'm just going to sub that out to a remediation company. Its at their minimum job size of $3000. But that means less demolition for a general contractor to do, so the real cost differential may be more like $2000 or less overall. Worth my peace of mind. Its important to keep in perspective....the drywall (really called rock lathe in this application) is about 40% of the total wall thickness. And it's <1% asbestiform. So even if it actually approaches 1%, its really only .4% of the total wall material. Inhaling the ground silica dust from the plaster is as bad or worse really. The test requirement is actually by layer, if any layer is 1% or greater then the whole system would be treated as positive. Oh, and I called 2 different environmental companies and told them what I had been doing, really concerned. I have 3 kids after all.... They could have sold me on $800 worth of air sampling and testing in the house for "peace of mind." But they basically told me its already settled out whatever little was there. Wipe stuff down. Vac up with a HEPA. And "go and sin no more" Again, I really want to stress that the type matters. I've read a good 5-10 research papers on the stuff from medical journals. A one-time exposure to amphibole asbestos in a heavy enough dose could be the death of you in 30-40 years. There are some horror stories. So avoid that stuff, really; but don't go billowing up clouds and say "hey its only Chrysotile". But, see, there are exposed rock formations with amphiboles in them, right in our area. The stuff is on the wind in very very trace amounts. If the "single fiber theory" was true for amphibole, they'd literally be stacking bodies like cordwood from it. Measured caution and respect for risk is key...neither paralyzing fear nor utter carelessness. (I also took the asbestos cement siding off my house back in 2006. Also chrysotile. If you don't break them up, there's no issue. I just wore my HEPA mask and kept them wetted, bagged them up. They even take them at the dump in the bags. Then... the siding crew came and just ripped off the stuff of the shed dormer triangles that I though they would cover over. Threw it all in their truck without gloves, a mask, or anything at all. On their own accord. I just rolled my eyes.) |
Anonymous
| OP, we are under contract for a 1920s house with plenty of plaster and are getting ready to have to rip down a ton of wallpaper and otherwise disturb the walls, so this is really helpful. We'll also get an opinion during our home inspection. Thanks. |
Anonymous
Glad I could be of help. Test assured, then you can rest assured. Any inspector that dismisses it as a possibility needs to be informed. And he/she shouldn't be totally blamed...after all even the EPA just lists "popcorn ceilings, acoustic tiles, floor tile, mastic, siding, and pipe insulation" as basically the only types to be found in a home. No run-of-the-mill plaster walls. As much as anyone of us think we know, we're all still learning. |
Anonymous
| Thanks for posting this OP. Very helpful! |
Anonymous
| I would worry much more about radon than asbestos. Of the lung cancer deaths in the US, about 95% are attributable to smoking tobacco, 4% to exposure to radon in mining operations and asbestos and other enviornmental dangers comprise 1% of the lung cancer deaths. Glad you dodged that bullet OP |
Anonymous
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OP, I asked the question about the year of your house. This is freaking me out as ours was built in 1946, and we had to have pipe work done to bathroom pipes because of a leak.
It's amazing how most people in the business don't know this stuff. Good to know about future hole drilling etc. And, PP, I agree re radon. Thanks again-- will keep this in mind for future renovations. Good tip to include a remediation company. |
Anonymous
OP here. The types of pipes that were insulated with asbestos were usually HEATING pipes, not water pipes. Though hot water...who knows. But mostly for steam applications and radiators. Your plumber would have handled it appropriately, I would suppose. Plus a little pipe repair is different than a big tear out job. Just ask, and insist on testing in the future if you have any concerns. oh, and yeah I got a radon kit sent to me last week. company out of Frederick MD does them, they are far more accurate than the cheapo kits from the home center. Guess we'll see where that ends up. Our walk-out basement gets good air circulation though and we're not down there much. |
Anonymous
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Hey great research. I also have 1-2% crysotile asbestos content in our Lathe and Plaster walls. They were covered with drywall i assume in 60's or 70's. Not sure. THey dropped all ceilings a foot to save heating costs and cover up the deteriorating walls.
I tested a whole bunch of materials in the house. I assumed the 8 x 8 tile was asbestos so we didnt bother testing. When I bought the home we demoed the entire first floor down to the stud. I Bagged it all up in 2ply 6mil bags and labeled it, hauled it to a dump authorized for disposal. We created as best we could a negative pressure space by sealing the space. I rented an air scrubber for $150 a week to constantly blow air out of the space. The scrubber had a hepa filter. I used a small shop vac with hepa bags and filter as well. We wet the material at first. but gave up on that after a while. For personal protection we wore eye pro and P100 hepa masks. Not the cheap kind as you mentioned. We took some protections, but could've done better. I felt that since it was a one time thing, get it done, and move one. We moved in a week later, and have been living in here since April 1. That's now, 7 months. We've been working on the house a lot, but still down to the studs in Living room and Kitchen. There is some exposed plaster but its not agitated, except the small pieces that breakaway from time to time from vibrations. We do our best to vacuum and dust often. I run a large Hepa air filter all the time downstairs. Its probably undersized for the volume, but again better than nothing. We had windows open all summer. Now were butting down for winter, which will be cold in here!! I got to thinking about the hidden dangers in our walls. I was happy relieved to see you talk about Crysotile Asbestos not being as much of concern as the Amphibole Asbsestos. It still makes me nervous to be living in this house as we work on it. |