How-to guide

How to record damp meter readings

A single damp meter reading doesn't tell you much. Readings taken the same way at the same points over weeks tell you whether a wall or floor is drying out - or getting worse.

Published 8 Nov 20264 min readBy metre2

Quick answer

Take readings at fixed, marked points, record them by property and room each time, and judge the trend rather than one number. Open the Metre2 Damp Meter Log in your browser - it's free for 15 days, then a one-off price, and nothing you type is uploaded.

Fix your points

Mark or photograph where you take each reading - height above the floor, distance from a corner - and use the same points every time. Readings a few centimetres apart can differ a lot.

Same meter, same setting

Most pin meters are calibrated for timber and show wood moisture equivalent (%WME). On plaster and masonry the number is a relative indication, not a true moisture content - so compare like with like and don't mix meters.

Watch out for salts

Salts left behind in plaster by old damp attract moisture from the air and can give high readings in a wall that's actually dry. If readings stay high long after a leak is fixed, get a proper survey.

Read the trend

Record the date and reading each visit. Steadily falling numbers mean it's drying; flat or rising numbers mean the cause is still there.

Do it in the Metre2 Damp Meter Log - 15 days free in your browser, or as a Windows app.

Use it in your browser - free, no sign-up Get the Windows app More about Damp Meter Log

Common mistakes

Taking readings at different points each visit.
Reading %WME on plaster as an actual moisture content.
Deciding from one reading.

Frequently asked questions

What counts as damp?

It depends on the material and the meter. The app's dry, at-risk, damp and saturated bands are a quick guide to the trend; for a diagnosis, use a qualified surveyor.

Can it show the trend?

Yes. The Damp Meter Log records readings by property and room, draws a trend line for each room and shows dry, at-risk, damp or saturated bands.