Moisture Meter Readings

[Jim Dull]

The house I inspected yesterday gave off high readings on the moisture meter on most of the walls, including inside walls. The walls appear to be some kind of plaster coating over drywall. I used the drywall setting and the meter went wild. If I used the plaster setting, the reading was normal. There was no evidence of leaks anywhere, including the roof, plumbing, or around windows. No moisture stains on ceilings or walls, no rust or mold in window sills, etc. I'm not sure how to report this. Any suggestions?

[Richard Rushing]

Are you using a deep penetrator (I do:p )... Tramex MEP and Surveymaster.

Was it a nice stucco exterior??

Rich

[Scott Patterson]

What type of moisture meter?

How high or percent of moisture did you find? Was it the same all over the house?

Did the home have an A/C system and if so was it working properly?

Did you notice high humidity in the home or outside?

Any pictures??

[Jim Dull]

Tramex Moisture Meter Plus. No, I did not use the penetration. Yes, the stucco was excellent. The readings were all over the house except for the kitchen area which was recently redone and did not have the stucco finish. The readings were well into the red zone and the alarm sounded. The A/C was working properly. The humidity was high on the outside but did not seem to be on the inside. No pictures except for inside closets where there were several small holes and which was drywall and tested normally.

[David Banks]

Jim. You may just have had it on the wrong setting. My Tramex Moisture Encounter Plus will do that. I just got mine so I am not an expert. But as Scott Peterson recommended to me experiment around your house. Metal corner bead will set it off.

[Scott Patterson]

If you did not get a high reading on the redone kitchen walls, I would say that the finish on the walls is giving you a false positive reading.

[Jerry Peck]

The walls appear to be some kind of plaster coating over drywall.

You are, I presume, referring to interior walls (because you said "drywall"), could be a one coat veneer plaster coating over special gypsum board (drywall). Usually, the gypsum board used for plaster is 'blue board', which has a 'bluish color finish', hence its name. The special paper on blue board allows the plaster to adhere better and provides for better and easier application of the plaster.

The "plaster" setting, I would think, would be for 'real' plaster, three coat stuff. It is possible that the veneer one coat plaster is dense enough to change the readings when set to "drywall".

[Eric Barker]

Jim,

I've been using Tramex meters for years and one thing that I've learned is that the meters can mislead you. If you're getting the same readings throughout and you don't have water/moisture problems in a basement or crawl then I have to think the meter should be ignored. Having high readings all over is exceptionally unusual and worth doubting.

I always use the meter on a relative basis. If I have moisture readings in the ceramic floor away from the toilet I notch the sensitivity down and try it again. Unless I can get the meter to give me a low reading somewhere I am not going to put much faith into what it's telling me.

[Rick Hurst]

Jim,

Just a few thoughts.

Had the carpeting been cleaned recently? Like in the last few days.

Or fresh paint on the interior walls.

These things can raise the humidity up in the home.


Just thinking,
Rick

[Jerry Peck]

I always use the meter on a relative basis. If I have moisture readings in the ceramic floor away from the toilet I notch the sensitivity down and try it again. Unless I can get the meter to give me a low reading somewhere I am not going to put much faith into what it's telling me.

Precisely the way I used my moisture meters - relative to other like areas, even for drywall walls. Check several like areas 'known to be dry', i.e., where there is no logical reason for them to be other than dry, then compare that to the other areas you suspect problems. Caution though, do not compare exterior walls to interior walls, which is why I said "like areas" - you want the wall construction to be the same (frame/frame or CBS/CBS) and the environment on the other side of the wall to be the same (indoors/indoors or outdoors/outdoors).

[Jim Dull]

Thanks to everyone. I tend to be a technological moron. Sometimes I think even my screwdriver is smarter than I am.