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Moisture Content in Drywall

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[#1] Posted: 05/01/2007 - 9:31:39 PM
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What is an "acceptable" level of moisture content in drywall?

A few hypothetical scenarios:

If one gets an elevated reading along the bottom of an interior basement wall, is it a problem?

If one gets a "100%" (the metter is pegged) along a basement wall, but there isn't any visible mold, mildew or water damage for a year or so, is it a problem?

What are some good resources for researching this?

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Moisture Content in Drywall
[#2] Posted: 05/01/2007 - 9:56:06 PM
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It depends on what type of a device you're using.

I use a Protimeter SurveyMaster of 1999 vintage. If I'm testing drywall at the base of the wall on a main floor in this climate, and it's dry, I usually get a reading of about 8-9%. In a daylight basement, I'll typically get a reading of about 10 - 11% and in a full basement about 12 to 14%. I don't get wound up about it, though, until my meter hits 19 - 20% or higher.

If I saw it pegging at 100%, I'd expect there to be an issue there that warrants some type of invasive inspection.

ONE TEAM - ONE FIGHT!!!

Mike

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Moisture Content in Drywall
[#3] Posted: 05/02/2007 - 6:36:52 PM
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It all depends on the relative humidity (RH) in the room and the depoint. If you are finding 100% relative moisture in gypsum drywall, I would think that it has a problem. The gypsum I would think would be fairly soft and give little resistance if it was probed. As for mold, don't forget that you are only looking at one side of the wall. The other side could be a festering colony of Who's Who in the world of mold.

On hot humid days in the South I have found moisture readings in the high teens in garages and in homes with no A/C. Never anything over 20%, unless another problem was present.

A second thought; could it be possible that you are getting a false positive reading? I have had this on occasions, sometimes from the paint on the walls to metallic wallpaper.

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Moisture Content in Drywall
[#4] Posted: 05/02/2007 - 9:15:22 PM
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Thanks for the responses.

For some reason, the last 3-4 days has been bonkers! Four phone calls with folks asking my advice and opinions on their drywall moisture issues.

The scenarios I posed aren't situations I personally discovered, however have had similar experiences in the past, all with no conclusive outcomes.

Just wanted to know others' experiences.


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Moisture Content in Drywall
[#5] Posted: 11/28/2011 - 8:21:04 PM
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I know this is an old thread but this is the only place that I could find info on the moisture content of drywall on a decent forum. So I'm in a rental Unit daylight basement on well water. The well water pipes going into the house have shut off valves sticking out of the drywall in a bedroom backed against the buried wall of the house On the other side of the wall is the bathroom with good ventilation but the dryer vent is just going right into the drywall. I was moving a bed into the room and I leaned against the wall with my hand and the drywall gave way leaving a hole in the wall. The wall is really soft but not wet to the touch and there is a toilet in the bathroom on the other side of the soft wall also. I think the toilet is leaking because the base board is starting to come off the wall. The other tenant upstairs has mold growing on his wall and I believe it's right above this wall. My landlord isn't very good with fixing things properly and always does it himself. Does anyone know if my landlord is legally obligated to fix this problem? If so where could I find the info. At this point just to hear someones opinion that doesn't think that I'm making a big deal out of nothing would be nice.

Thanks, Josh

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Moisture Content in Drywall
[#6] Posted: 11/28/2011 - 9:39:54 PM
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Josh,

If you need advice on identifying and/or correcting problems with buildings, this would be the place. The only question in your post is asking for legal advice. You'll need to ask a lawyer.

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Moisture Content in Drywall
[#7] Posted: 11/28/2011 - 11:52:23 PM
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I'm not offering any legal advice, but both you and the landlord are subject to WA's Residential landlord-tenant act, which you can find at http://apps.leg.wa.gov/RCW/def...te=59.18 .
There is an easier to read synopsis of your rights at http://www.lawhelp.org/documen...rev=/WA/ . It includes suggested steps you should or could take (including getting a lawyer involved).

Obviously, neither can cover every specific issue that could occur within a house. You can follow certain steps but I suspect it gets "messy" when the landlord actually responds, but with half-assed repairs.

On the problem itself...if your hand went through drywall just by leaning on it then, yeah, it sounds like a real issue. Of course, if you really punched the hole.....??? Also, what do you mean when you say "the dryer vent is just going right into the drywall?" Is it not ducted and terminating outside?

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Moisture Content in Drywall
[#8] Posted: 11/29/2011 - 05:18:11 AM
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A house in Bellevue on well water. . . (?). . .

That's a red flag for me. To me that says oooold place that's still stuck in the. . . .40's?

Bellevue, WA - Washington
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Moisture Content in Drywall
[#9] Posted: 11/29/2011 - 09:09:45 AM
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It is ducted right into the wall and there is a vent going outside but the vent had been taped up for years because someone thought that rats would be getting in there, and no I didn't punch a hole in the wall, I was leaning over a box put my hand on it and it gave way. As far as the well goes all of the people on it just put $15,000 in updating it and I just ran new pipe from the well to the house for a break on rent and the water has been tested and is great.

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Moisture Content in Drywall
[#10] Posted: 03/09/2016 - 12:17:59 PM
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My contractor used a moisture reading apparatus to measure the moisture content in the bathroom drywall and it read 2.95. he than measured the moisture contend on the hallway drywall and it was 1.75. Since we had experienced a pipe leak in the bathroom I am concerned that if the drywall is still wet there is a probability of mold contamination.
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Moisture Content in Drywall
[#11] Posted: 03/09/2016 - 12:51:44 PM
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Quote: Originally posted by raquel

My contractor used a moisture reading apparatus to measure the moisture content in the bathroom drywall and it read 2.95. he than measured the moisture contend on the hallway drywall and it was 1.75. Since we had experienced a pipe leak in the bathroom I am concerned that if the drywall is still wet there is a probability of mold contamination.


Ask him what a "2.95" reading means. Is the contractor in the business of mold remediation? When did you last take a shower in that bathroom? Was the reading the same in all places? So many variables, so little time.

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Moisture Content in Drywall
[#12] Posted: 03/09/2016 - 3:03:20 PM
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I don't really ever look at the numbers on my meters. "Dry" drywall barely registers, and wet drywall pretty much pins the needle. If 1.75 is dry, 2.95 doesn't sound much higher. It's possible he put the meter over a stud, a pipe, a wire, a drywall screw, a piece of metal cornerbead, or something else. It's also possible the moisture content in the bathroom is slightly higher. He should take several dozen readings in various areas, high and low, to get a picture of what might be going on. In general, if the leak has been fixed, the materials will dry out without a problem, and I wouldn't worry about it.
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Moisture Content in Drywall
[#13] Posted: 03/09/2016 - 3:55:51 PM
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What Hockstein said. What's 2.95? Percent?


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Moisture Content in Drywall
[#14] Posted: 03/09/2016 - 4:25:45 PM
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More likely, the dry areas are 17.5 percent and the damp area is 29.5 percent. Yes 29 is damp for drywall.

You should have heat on in that bathroom and the door open. Feel the wall with your hand. It will dry out slowly unless the drywall is super-saturated.

   
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