In the annual timber pest inspection report, there is something about high moisture levels being detected in the shower walls together with these photos: enter image description here

I recently re-seated the shower taps and fitted new ceramic spindles, then resealed the whole shower area. It was around two months ago so any water that dripped inside the wall should have dried by now. In addition, I don't see any sign of water leakage anywhere, particularly at the lower level under the shower. The only thing the inspector who produced the report says is that I need to get an invasive inspection done.

How reliable these moisture measurement tools are? Is there any way for me to find out whether there is actually any water leakage inside the walls without breaking the tiles?

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    LOL @Mazura! Looks like an analog multimeter. If there was a long-sleeve in the pic, I'd suspect he had it set to continuity with the probes up his sleeve and taped together. I dunno what that's measuring.
    – FreeMan
    Commented Feb 25, 2022 at 0:42
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    The device used in the photos is: tramexmeters.com/perch/resources/downloads/user-guides/…
    – Reza
    Commented Feb 25, 2022 at 1:14
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    It's difficult to be sure from the fuzzy pics, but it looks to me as though your guy has the meter set to "Scale 3", while the instruction manual which Reza linked to specifies that ceramic tile should be tested on "Scale 2". It also says "As calibration is not practical because of the variation in composition of these types of construction, tests should be carried out on a comparative basis selecting the most appropriate scale, and readings should be taken from the 0 to 100 comparative scale on the meter dial." - so I'd be interested to see what the meter read elsewhere on that wall too.
    – brhans
    Commented Feb 25, 2022 at 1:49
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    Do you have access to the back of the wall or is this an exterior wall? Even exterior it can sometimes be easier, depending on the siding, to inspect inside the shower wall. You could drill a hole in the grout and use an endoscope camera to look inside the wall cavity and then just patch the grout. Commented Feb 25, 2022 at 9:27

1 Answer 1


A surface measurement is not a clear indication of the state of the interior of a wall.

Behind the tiles is thinset tile adhesive and behind that hopefully something waterproof, but a simple measuring device like that pictured will not be able to determine which side of the waterproofing the dampness is on.

It's probably just the thinset and tiles that are damp, and this is not a problem.

If that's not actually tile but instead a manufactured single-piece shower panelling with a tile look then yes worry. that should be dry.

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