How to use a moisture meter on a wall or a log
Updated: October 2026
The meter is in your hand, the wall or the log is in front of you, and one percent on its own will not tell you anything you can repeat tomorrow. How to use a moisture meter, on the pin and pinless models in this set, is mostly about keeping the mode, the pressure and the spot the same. Products Compared used the amazon.co.uk extracts and public UK method notes on 16 October 2026. We did not visit your house, and we did not lab-test the twelve meters in the [moisture meter comparison](/hub/measuring-equipment/moisture-meter).
The meter is in your hand, the wall or the log is in front of you, and one percent on its own will not tell you anything you can repeat tomorrow.
The meter is in your hand, the wall or the log is in front of you, and one percent on its own will not tell you anything you can repeat tomorrow. How to use a moisture meter, on the pin and pinless models in this set, is mostly about keeping the mode, the pressure and the spot the same. Products Compared used the amazon.co.uk extracts and public UK method notes on 16 October 2026. We did not visit your house, and we did not lab-test the twelve meters in the moisture meter comparison.
Our top picks
| Badge | Product | Sensor | Hold | Batteries | Note | Price | Offer |
|---|---|---|---|---|---|---|---|
| Best overall |  RDINSCOS RDINSCOS MT19 | Pin | Yes | 3×AAA included | 9.2 | about £20.99 | View offer |
| Preis-Tipp |  COCZOW COCZOW PM6811A | Pin | Yes | 2×AAA included | 9.0 | about £17.99 | View offer |
| Alternative |  Mecurate Mecurate pinless PDM-01 | Pinless | Not stated | 3×AAA included | 9.0 | about £24.99 | View offer |
On this page
Set the meter before you touch anything
Fit the cells the listing actually requires, then leave the pins or the pad in the air. Elitech says the MOT-270W calibrates at switch-on if the pins touch nothing. Select the mode for the material, not the mode you used last on a log. Hold should be off. HAVENWARE's table says batteries are not required, and UK reviews say the meter needs 2×AAA. If you bought through our amazon.co.uk links, a qualifying purchase can earn a commission at no extra cost to you.
On a wall
Find a spot on the same wall that looks dry and is the same finish. That is your reference. Faithfull warns that salts, foil-backed plasterboard and aluminium paint can raise conductivity. Safeguard's method is to build a profile with example spacing of about every 300 mm. Faithfull uses about every 100 mm. Neither spacing is a British Standard, so pick one and keep it. On a pin meter, seat the pins with even pressure and do not wander into a cable or a pipe. On a pinless meter, keep the pad flat. A single high percent is not the name of the cause. The limit is on the damp meter for walls page.
On wood
For bare timber, pins go across the grain, with enough contact that the number settles rather than flickers. Woodsure says to measure as soon as you have split the log, pins across the grain, and to wipe surface water off first. Forest Research uses three points on the fresh face, about 5 cm in from each end and one in the middle. That is a household indication, not a supplier's certificate. A pinless pad on bark is reading the outside. The England 20% figure is on the moisture meter for firewood page.
Write the number down
Write the mode, the spot, the time and the percent. If the meter has hold, use it to freeze the figure while you write, then clear it before the next spot. Three spots on a log, or a small grid on a wall, is the minimum that lets you see a pattern. If you come back next week, use the same mode and the same places. The buying guide is where you check that the scale exists.
When the number looks wrong
A screen stuck on one figure is often hold, a flat battery, or pins that are not in contact. A jump when you slide a pinless body is a contact problem before it is a new leak. The Valiant file includes a review of no reading when the wood was warm. Let that log cool, split a fresh face, and try again. A beep is the maker's alert threshold. It is not proof of rising damp.
Common questions
How do I use a pinless meter differently?
Keep the pad flat and still, on the mode named for wall or masonry. There is nothing to push in, and there is also nothing to tell you that you have reached a solid contact except a stable number. Slide slowly if you are mapping, and write the spot, because the reading can change as the body moves. The percent is still relative. Mecurate says building figures are reference only. Neoteck says wall and masonry are relative.
What if the screen stays on one number?
Turn hold off, move to open air, and see whether the figure changes. If it stays, refit the batteries and check that a pin meter's probes are actually touching the material. Kiprim's 0% on plaster is the sort of result that needs those checks before you decide the wall is dry. A pinless meter held at an angle can also stick on a poor contact. Clear the reading, then take the spot again.
What if plaster reads 0%?
Treat 0% as a failed contact or the wrong mode until you have checked both. Confirm the building or wall mode, seat the pins, and clear hold. Compare with a timber offcut if the meter has a wood scale, so you know the unit is alive. A genuine dry surface is possible, and a single zero is a weak way to prove it. If a second spot on the same wall also reads in a way you can repeat, write that down as the start of a profile.
Should I press harder if the number is low?
No. Extra force bends pins and can snap them, which already shows up in reviews of hardwood and floorboards. You need enough contact for a stable figure, not a higher one. On a pinless meter, pressing harder does not push the field much deeper than the listing's stated depth, where a depth is stated at all. Change mode or spot before you change your grip.
When do I stop and look at the damp-walls page?
Stop when you are about to name the cause, to inject a wall, or to decide a purchase from one percent. The how-to gets you a repeatable pair of spots. The damp-walls page is the limit on what those spots mean, including salts and a meter that stays high after a new damp-proof course. Widespread mould, a dispute, or a wall that stays wet after the leak is fixed is a job for a surveyor, not for another button.
Related pages
Sources
Public UK sources on timber moisture, Ready to Burn in England, and damp readings in buildings. Prices, stars, and review counts are the amazon.co.uk listing figures in this set. Prices move. There was no laboratory test and no oven-dry calibration. Last checked 16 October 2026.
- GOV.UK, selling wood for domestic use in England (retrieved 16 October 2026)
- SI 2020/1095, domestic solid fuels standards in England (retrieved 16 October 2026)
- Property Care Association, code of practice for dampness in buildings (January 2023) (retrieved 16 October 2026)
- Property Care Association, use of moisture meters to diagnose dampness (retrieved 16 October 2026)
- BS EN 13183-2:2002, moisture content of sawn timber by electrical resistance (retrieved 16 October 2026)
- BS 5250:2021, management of moisture in buildings (retrieved 16 October 2026)
- Approved Document C, resistance to contaminants and moisture (retrieved 16 October 2026)
- Forest Research, a simple method for testing moisture content (retrieved 16 October 2026)