I am so happy you asked. I have wondered the same because agriculture gypsum is said to improve tilt of clay.
A secoundary question might be wherether it will aggervate akline soil conditions.

This question does appear periodically and the general answer is no because of the additives, adhesives, fillers, etc., in the drywall. Drywall is not just gypsum. You will, however, find a large number of people that will say it is okay to do that. I would not want my soil contaminated by more potentially bad stuff.

So the general answer is ambiguous, IOW.

I am one of those who has used drywall scraps plenty and never noticed any problem. But OTOH one rarely knows why a specific crop problem happens, just as one rarely knows exactly why a plant thrives.

In other words...Fill the landfill....uh, I guess.

Gypsum is good for certain kinds of clay soils, but otherwise it doesn't add much that's useful.

I just took Asbestos Inspector training so now I'm a certified inspector. Apparently drywall and drywall mud sometimes had asbestos added. Aaaand...are you ready for this... sometimes still does! One more rock on the 'don't-use' side of the scale.

Added note: My local municipality does take clean unpainted drywall scrap, shreds it and adds it to the city compost. We do have heavy clay that benefits from gypsum, and I've used the compost. It does have borax as a binder so heavy use can lead to too much boron which plants don't like.

There are numerous threads here about this if you search 'drywall'.

One could use it for fill in a ditch if not in a garden

This post was edited by toxcrusadr on Fri, Jan 24, 14 at 13:56

Tox, I'm interested in your statement about asbestos in new drywall (since I am often around it on job sites). I should think it would be easy enough to learn which manufacturers would be doing that. My understanding was that any form of asbestos that can lead to micro-fibers in the air was outlawed.

I'm wondering if asbestos being a natural mineral fiber is commonly in soils. I'm also wondering if the asbestos 'scare' of several years ago was over-rated a bit. I can see where long term daily exposure to the dust could be bad.

It would seem hard to me to check for astbestos. There are air samplers, but do you have to take swab samples?

According to a site I was just reading, some guys routinely test old material before ripping out of old buildings. As I from time to time demo old drywall (pre-1980 it seems, generally had asbestos in the joint compound), maybe I'll start having it tested as well. it's a few hundred dollars to test, apparently.

Pre 1970's drywall manufacturers added asbestos fibers to the mix for strength, Today fiberglass fibers are used. Other additives provide water resistance, fire resistance, etc. Many states require scrap drywall, along with other construction debris, to be placed in special landfills and not just any place because of the potential hazardous nature of the material used to make the stuff.
There is no ambiguity about what to do with drywall scraps. Do not put them in your garden.

Here is a link that might be useful: how drywall is made

Kimm, your link is not authoritative and does not mention asbestos in any case.

According to what I read pros in the drywall trade say that asbestos was never used in drywall but usually was in joint compound. How this could be verified with some degree of reliability other than testing specific material, is unclear.

pnbrown wrote;
"According to what I read pros in the drywall trade say that asbestos was never used in drywall but usually was in joint compound. How this could be verified with some degree of reliability other than testing specific material, is unclear."
All my information also says joint compound was the only place asbestos was used. If you shop labs you can have samples tested quite reasonably for lead and asbestos.
I don't want to debate hazardous material here but simple suggest you get reliable first hand information before routinly testing jobsites. Once you discover hazardous material,you become it;s custodian if you remove it and that is a legaly risky undertaking unless you and your employees are trained. Nuff said,the rest is up to you.
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Ok back to gardening. I have heavy clay and plenty space so I think I will apply lots of ground drywall scraps to an area to compare soil and plant results. I believe totaly avoiding that from demolition makes sense considering you can get far more new than you could ever use. A person would realy cut a fat hog finding use for the tons going to disposal sites.

Mr. Brown, perhaps this link might be of some assistance to you.

Here is a link that might be useful: Asbestos in drywall

I started in the trades in the early 80's, I hung drywall for a while and have sucked up my share of joint compound dust, but nothing compared to guys who have been tapers for decades (almost always those guys smoke as well, so it could be hard to pin their respiratory problems strictly on the asbestos). The fact is that all fine dust is terrible stuff. I worked in my woodshop without a dust-mask (inexplicably) for about 5 years until a breathing problem woke me up.

Now I wear the dust mask at all times in shops and on job sites too if it is dusty - such as installing trim in houses that were just drywalled - the compound dust is all over and any activity stirs it up.

Back to the OP: a little thought would indicate that even if there are fibers in the drywall, the stuff is damp once it's been on the ground for a while so there won't be any airborne dust. Does anyone imagine that asbestos fibers can pass through plant roots and become incorporated into leaves or fruit?

"Does anyone imagine that asbestos fibers can pass through plant roots and become incorporated into leaves or fruit?"

I see no way it could,but come to think of it I've never read warnings about ingestion so it seems mute anthow.
Unlike fine dust ,some of which mixes with mucus and caughed out,the effects of asbestos is cumlative meaning as I understand it,what go's in never comes out and 1 hour of inhalation per week for 7 years is equilivent to 8 hours per day for 46 days. A man could consume a box of rat poision in small amounts over a span of time without ill effects on his body.

You might want to read the attached link before you completely decide - gypsum is not necessarily the magic de-claying product many assume. And to take it a bit further, gypsum board (sheetrock, drywall, etc) has a lot more in it than just gypsum. Essentially it is a gypsum-based paste sandwiched in between layers of paper or thin fiberglass sheets - but it will also contain fiber (typically paper and/or fiberglass), plasticizer, foaming agent, finely ground gypsum crystal as an accelerator, EDTA, starch or other chelate as a retarder, various additives that may decrease mildew and increase fire resistance (fiberglass or vermiculite) and wax emulsion or silanes for lower water absorption and water. Some or all of these may not be welcome in an organic garden.........

Here is a link that might be useful: The myth of gypsum in the garden

Neither Asbestos fibers or fiberglass fibers will be taken up by plants so they can be ingested. However, those fibers will be in the soil where the gardener, or their children, can stir them up and inhale them.
I too have had drywallers tell me that there was no Asbestos used in the manufacture of that drywall simply because they did not want to deal with the problem. It is much easier to ignore Asbestos then to properly handle it.

Apparently I started quite a discussion here. It's a bit far afield from the original question, but since it grew legs, here's what I know.

I don't have any actual references regarding asbestos still being used in products. I doubt it is all that common, and the products would almost certainly be imported as no US company would risk the liability (IMHO).

Our course instructor, who has been in the biz for 30 years, said that there is nothing actually prohibiting the use of asbestos in products. I am not sure I understand this, but working in govt enviro regulation myself, I can testify that what is in (and absent from) regulations can be quite surprising. In any case he actually recounted a case of a company that hired his firm to do an assessment on one of their buildings. He found asbestos in drywall or mud one area, and the company was unhappy with the result because it was an area they had remodeled fairly recently. I don't have the details on what 'recent' is, nor do I have any proof regarding a specific product. In any case we were advised always to test drywall/mud/tape materials unless they were certified asbestos-free.

Last year I used scrap drywall in two ways.

was putting in a new limestone driveway and layer the scrap drywall down first . I figured it would prevent weeds from growing up through the limestone, at least for a while. It worked. Weeds did grow up between the seams.

Since that worked, I used some more for sheet mulching. I topped the drywall with pine straw. It kept the weeds down. I will probably push back the pine needles soon, to see how the sheet rock is holding up; just out of curiosity.

As a bonus, I saved the disposal fees.

I am about to do another large sheet rock job, so I will have a good pit of scrap. I will probably use it as sheet mulch again in the flower beds.

btw, as to the original question, I would not put it in the compost. Not because of safety concerns, but due to the fact that I don't think sheet rock will actually "compost." The paper on the outside might, but the gypsum will not break down any further, afaik.

The bottom line is that unless you have a sodic soil (due to low rainfall) gypsum does nothing for your soil. Wallboard, Sheetrock, Gypsum Board, Plaster Board because of the additives put in for strength, fire and water resistance, and other properties is a potential source of pollution of your soil.

Elbourne, thanks for the first hand accounts. I wonder how permeable it really is to water - not sure I'd use it as a mulch where things are supposed to grow. Not to mention the boron problem.

I do like the driveway substrate idea though. It can't really hurt anything under there, and if someone wanted to change the use of that area to something else, like a garden, the drywall would end up being stripped off with the limestone anyway.

I agree it will not compost, except for the paper layers. Our city shreds everything pretty fine so all you'll see in their compost is a few tiny bits of white. I would not try to put it in a home compost pile.

I'd pass. No real reason. It's just that I'm more of a 'only compost something that once grew' kind of guy. Sure this stuff may have been part of some kind of living thing waaaayyy back, but it's still just rock to me.

Lloyd

So Kim, have you tested the drywall and compound in your house?

Many of the walls and ceilings are plastered and that has horse hair added for strength, but none of the drywall
I put up has Asbestos (tested) although it does have fiberglass. None of the joint compound had either.

After so much turns and twist ( from drywall having hazardous material to not being so useful to deal with clay soil etc) , Now we know with almost NEAR 100% certainty that:

== drywall does not have an asbestos or any potentionally harmful substances.

== Even if if di have asbestos, it would only be harmful in dust form. And that is unlikely to come out of garden soil in substantial quantity. And since any of the additives in drywall is not taken up by the plants, there no risk in eating them.

I, personally, am 99.99% sure now that I can add drywall to my potting soil , in my beds ( I will get it from the scraps in construction sites, FOR FREE) without a worry.
THANKS FOR THE DISCUSSIONS.

I would consider fiberglass fibers as hazardous, especially since I know 5 people awaiting lung transplants because of the fiberglass in the lungs they now have which makes breathing as difficult as Emphysema. Since the additives in drywall, the adhesives, fire and moisture retardants, etc. are not meant to be eaten or put into gardens there are no tests to determine how hazardous they are in those contexts, but most are listed on shipping papers as hazardous chemicals.
Putting these pollutants into your soil contr4ibutes to the pollution of the water I get.

i am wondering about making a parking spot by laying drywall scraps on the ground and just driving on them; also i have wondered about putting them around trees before placing mulch.