# What is this stuff?



## Bud Cline (Mar 12, 2006)

It's a form of plaster.
The tiny fibers are asbestos.
You can do what you want.


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## IdahoEv (Aug 21, 2012)

I didn't see anything fibrous, just something cement like. Is that stuff definitely asbestos? Do I need to call an asbestos pro?


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## Bud Cline (Mar 12, 2006)

Years ago when plaster was applied over wooden lath strips, horse hair was used to bind the mix and help to unitize the cement product. Go figure!

Then later the lath sort of went away and after WWII they started using mostly drywall backer board like you have. Around that time the horse hairs were replaced with asbestos fibers. The fibers were basically the size of horse hairs and slightly smaller. I'm thinking the vintage I see in your photo would have contained asbestos but maybe not.

Too late now to worry about it. In most all cases any threats from asbestos would be directed at workers using the mineral and working with it over a long period of time. Some people these days freak needlessly at the mention of asbestos and they over-react. Some asbestos abatement companies like to use fear tactics to persuade consumers to use their services. I'm not saying there isn't a threat I am just saying that the danger is in the eyes and fears of the handler. Years ago when I was certified as an asbestos abatement contractor I learned a lot about the product and quite frankly I wouldn't be at all concerned doing your project. This is a judgement-call and you have to make the call.


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## IdahoEv (Aug 21, 2012)

Okay, good to know. How do I go about cutting it? The stuff destroyed my jigsaw blade in moments, and I still have three sides of the hole to square up. I also need to cut above and below a horizontal stud ... normally I'd do those cuts with a utility knife but somehow i doubt that would do it here. Maybe a chisel for those spots.

At least discovering this stuff explains one thing. Pulling out a picture-hanging nail in this house always results in a half inch wide crater, no matter how careful I am. I though it was just crappy ancient drywall.


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## Bud Cline (Mar 12, 2006)

There are blades made with a carborundum (grit) edge, those are your best bet but you may still gobble-up more than one blade.

I use a 4" angle grinder with a diamond blade but dust is a huge issue when doing it that way.

You could also use an angle grinder with an abrasive (masonry) blade.

I would not do too much pounding with a chisel if it isn't totally necessary. Just my thinking.


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## chrisn (Dec 23, 2007)

For sure , wear a mask


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## bbo (Feb 28, 2010)

and feel free to mist with water to keep the dust down.


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## gregzoll (Dec 25, 2006)

Rock-Lathe/Gyp-Rock.


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## joecaption (Nov 30, 2011)

I use a Roto Zip with a vacuum attachment and use a tile bit.
I have also cut it with what amounts to a small ciruler saw with a vacuum attahment with a diamond blade that also has a vacuum attachment so you can hook up your shop vac.


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## langless28 (Nov 20, 2011)

I think I have this stuff too. What is the technical name for it? Would gutting a hole kitchen be a bad idea if this was the walls?


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## gregzoll (Dec 25, 2006)

langless28 said:


> I think I have this stuff too. What is the technical name for it? Would gutting a hole kitchen be a bad idea if this was the walls?


As I stated before, Rock-Lathe, Gyp-Rock. Bad part is when you do not keep the dust from going all over the house.


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## langless28 (Nov 20, 2011)

The house is circa 1959 so I guess I will send a sample to get tested. I was not expecting this...


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## gregzoll (Dec 25, 2006)

langless28 said:


> The house is circa 1959 so I guess I will send a sample to get tested. I was not expecting this...


And it will come back as Gypsum, maybe some lead paint, cellulose and nothing else.


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## langless28 (Nov 20, 2011)

Well that would be a terrific result! So there's no chance of asbestos? Id rather be safe then sorry?


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## gregzoll (Dec 25, 2006)

Probably not. This is the list from mesothelioma.com of the products that contained asbestos http://www.mesothelioma.com/asbestos-exposure/companies/ I know that the Gypsum board used in my home did not, because it was made by USG (U.S. Gypsum). How did I find that out, it was stamped all over the backside of the board, and we could see it from the basement without tearing down a wall, where the product stamp was available to find that info.


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## langless28 (Nov 20, 2011)

Appreciate the thorough responses, I'll take some precaution and see if I can find a chunk with some markings. My father (retired contractor/architect) insists there is no asbestos either.


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## gregzoll (Dec 25, 2006)

If you go to mestheloma.com and do a search for the company name, it should return back a result.


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## Bud Cline (Mar 12, 2006)

If there is asbestos it won't be in the gypsum board, it will be in the masonry product that covers the gypsum board.


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## gregzoll (Dec 25, 2006)

Check the link I posted bud. National Gypsum was one of the companies that used a Gypsum board type product, that contained Asbestos.


"Many of these products were marketed under the "Gold Bond" brand name. Potentially dangerous National Gypsum products that contained asbestos included *wallboard*"
Read more: http://www.mesothelioma.com/asbestos-exposure/companies/national-gypsum.htm#ixzz26PKgf769
​


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## langless28 (Nov 20, 2011)

No manf. Stamps on my board, just "06256BK" it is also in 16" wide sheets. Numbers could be a date code? 56' and the house was built in 59'?

Edit:
Upon some google search for "bk" gypsum, there is a company called b.k. Plaster and gypsum corp over in Thailand. This company does not show up on that website. This all could be a guess though.

Edit 2: they may have been established in 1999 so maybe a dead end.


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## langless28 (Nov 20, 2011)

So in case anyone cares or as reference for future diy'ers. that type of wall cover has zero asbestos in the sample that i sent to the lab. granted every type and every place is difference but in my case, MY rock-lath, plaster, and skim coat contained no asbestos fibers.


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