Common Moisture Meter Mistakes
A moisture meter is one of the most important tools in woodworking and wood flooring. Used correctly, it helps you make sure your wood is ready to work with or install, so your projects last.
But like any tool, it only works as well as you use it. This article covers the different types of moisture meters, how to use them properly, and the most common mistakes people make with them.
When to Use a Moisture Meter
When trying to diagnose or prevent moisture problems in wood flooring and other wood projects, the obvious tool to use is a wood moisture meter, and the first obvious mistake is not using one. But there are several factors to consider when choosing the right meter and using the meter you’ve chosen.
Your choices can mean the difference between an accurate moisture content (MC) reading and a problem down the road.
Moisture Meter Types
There are two basic types of wood moisture meters: pin-style and pinless. Read more about the top differences between a pin-style vs pinless meter.
Pin-style meters use two narrow metal probes inserted into the wood you are testing. An electrical signal is passed between the tips of the two probes, and the meter converts the resistance measurement into a moisture content reading. Large hammer probes can be attached to a handheld meter for deeper measurements, since the probes are driven in by force, while shorter pins are usually pushed in by hand.
As the name suggests, a pinless meter does not use pins or probes. Instead, it uses an electromagnetic signal that changes depending on the moisture level in the wood being tested.
So, while the meter types are fairly easy to understand, several mistakes still keep these tools from being an asset on the job site. Some are problems that are inherent to certain meter types, but others can be easily avoided with a little knowledge. What should you watch for?
Common Moisture Meter Mistakes
Not Knowing the Reading Depth
With a pinless meter, it’s important to know how deep the meter reads. For example, if your meter is set to its 3/4-inch deep mode but you’re taking readings on installed 1/2-inch-thick flooring, the reading will be affected by the moisture content of the subfloor. That’s not a helpful reading to base decisions on.
Using Too Little Pressure
Pinless meters can produce inaccurate readings if they aren’t pressed down correctly. With too little pressure, an air gap under the meter’s sensor can affect the reading. Some lower-end meters are even affected by the position of the user’s hand. Press the meter down firmly so the sensor sits flat on the wood, but you don’t need to lean on it.
Note: When to Use Air Gap Behind a Board Being Tested
Wagner Meters’ Orion manuals recommend at least a 1-inch (25 mm) air gap underneath the wood you’re measuring, so nothing below the board affects the reading. The gap matters most in these situations:
When the Air Gap Matters Most
High moisture differential: When the board being measured sits on another board with moisture content 7% or higher than the test board.
Non-wood substrates: When measuring boards placed directly on materials that read as high moisture content, such as concrete, metal, or other materials that cause elevated meter readings.
Thin board measurements: When the test board is thinner than the meter’s specified measurement depth, since readings will be significantly affected by materials behind the test board. (On thin boards, several can be stacked to get a better average reading.)
When It Matters Less
When the board being tested sits on another board with similar moisture content, the board underneath has much less effect on the reading. Still, a 1-inch air gap is the most reliable way to get an accurate reading.
Important: Failing to use proper air gap spacing in the above conditions may result in artificially elevated moisture readings that do not accurately reflect the moisture content of the board you’re testing.
Breaking Pins
The obvious risk of over-stressing a pin-style meter is that pins can bend or break. Most pin-style meter manufacturers are clear that pounding or banging on the meter is not the correct way to insert the pins. Hammer probes are built to withstand more force, but even these more rugged pins can break over time, especially in hardwood applications.
Improperly Driven Pins
Pin-style meters (and even hammer probes) take considerable pressure to reach the proper pin depth. In softer woods, it takes little effort. But with many hardwoods, especially some very dense tropical species, driving the pins to the proper depth can be a real challenge, if not virtually impossible, particularly if your meter is not built to take that kind of force.
Bent or broken pins, or even cracked meter housings, become more common as wood density increases. It’s tempting not to drive the pins in all the way, but then the reading won’t be taken at the correct depth. A reading taken with pins close to the surface won’t reflect the moisture conditions deeper in the wood.
Trying to Take a Shortcut
Because pin-style meters take effort to insert and their pins can bend or break, it can be tempting to shortcut the testing process. That speeds up the testing but doesn’t give a true picture of the moisture conditions of the wood or wood flooring being used.
When testing large quantities of wood, or multiple bundles, it can be tempting to test only a few boards from the edges of the bundle.
Even in acclimated wood, moisture conditions can differ in areas with restricted airflow. Handheld pinless moisture meters, like the Orion® 930, let you scan lumber or wood stock to quickly gauge the moisture conditions across much of the wood. But if you don’t test a representative number of boards, the potential for trouble will still be high.
Overlooking General Maintenance
Any meter will suffer when exposed to high temperatures, overly wet conditions, being dropped, or other circumstances that damage the housing and the circuitry. But even something as seemingly minor as peeling insulation on the insulated pins of hammer-style probes can skew the meter readings.
Because the signal is then no longer limited to the tips of the probes, readings won’t be precise for depth. They may represent a composite of the signal along the length of the probe, or simply read too shallow based on where the signal is strongest.
Pinless meters may also give skewed readings if their sensors become scratched or damaged. Lack of regular maintenance can also affect the meter’s calibration. Wagner Meters’ Orion line of moisture meters can be checked and recalibrated on site in moments with the On-Demand Calibrator.
Not Using the Correct Species Settings or Species Adjustment
Most moisture meters use either user-programmed species settings or species adjustment tables. A piece of oak has different properties than Douglas fir, so the two need different species settings.
If your meter doesn’t account for those differences, its readings can lead to poor decisions about finishes or whether the wood is ready to install. Be sure you’ve read and understood the settings for your meter.
Free Download – Is a Pin or Pinless Moisture Meter Best For You?
Can a Moisture Meter Be Wrong?
A moisture meter can be an invaluable tool for choosing finishes and adhesives or for avoiding moisture-related problems in a finished project. But if it’s used improperly, a moisture meter won’t do the job it’s designed to do. Know your meter, follow the manufacturer’s instructions, and choose the meter that best suits your purposes. Then you’ll avoid those costly mistakes.
Accurate moisture readings go a long way toward the quality and longevity of your wood projects, and small mistakes in how you take them can lead to big problems later.
If you’re in the market for a moisture meter, Wagner’s Orion meters offer settings for different wood species and on-site calibration checks, and the Orion 930, 940, and 950 read at two depths.
As Sales Manager for Wagner Meters, Ron has more than 35 years of experience with instrumentation and measurement systems in different industries. In previous positions, he has served as Regional Sales Manager, Product and Projects Manager, and Sales Manager for manufacturers involved in measurement instrumentation.
Last updated on October 8th, 2026
800-634-9961
Hi, we have bought a Proster painless meter to use in our caravan and are not sure if it’s working properly. Would a pin meter be better, or what would you recommend?
Anne,
My apologies, I don ‘t understand what meter you have or what you are using it on. Could you be more specific?
Hello, Would magnetic magic paint make a pinless metre do high readings?
Tom,
If there is a metallic component in the paint, then it would cause high readings on both pin-type and pinless moisture meters.
Thanks!
The pinless moisture meter is only going off on the studs of the interior wall board of an exterior block wall? Is this likely real moisture or just it reading some sort of metal?
Kristen, the meter is not just reading the surface of course, but actually reading through the wallboard, and every time it sees a stud, the density alone of the stud being there is causing the reading to escalate, probably. Metal would have an even greater effect on the reading. With a pinless meter, you generally need an air gap behind the material that you are actually trying to measure.
Can a moisture reading be done on drywall? We had an inspector get a 100% moisture reading on a ceiling but when we opened the ceiling- it was completely dry inside. The wood and insulation was all dry. Can you tell us how/why the reader would possibly give a 100% reading? There was no metal in the ceiling and the meter was set to “wall”.
Ty, yes a moisture meter can be used on drywall but depends on the type of moisture meter. For instance, Orion moisture meters need to be set in the relative mode for non-wood materials such as drywall. What type (pin or pinless) and manufacturer of meter is it? Makes no sense to get a reading that high, ever.
Greetings. I am getting a few very isolated spots on my (already installed) hardwood floor showing moisture but dry everywhere else (using a fairly inexpensive pinless moisture meter).
I am wondering if those are possibly false positives? or if it is possible for a hardwood floor to have very small isolated moist (ie 35% moisture, which is where the meter maxes out) spots while the remainder of the board could be dry?
Let me know if you have any thoughts! Thanks!
MRK,
I would contact NWFA.org to have a certified flooring inspector come out and determine what the issue is. It is possible there is something going on below the floor and an inspector would find this for you. Thank you for writing in. Best of luck!
I’m getting a discrepancy between moisture readings and I am confused. Yesterday, I had a 3rd party certified mold inspector find high moisture readings in my bathroom floor using a pinless meter. Today, the building maintenance personnel found only low moisture readings with his 5/16in pin style meter. He kept putting it to his finger to “show us how sensitive it was” before taking a reading in the floor and surrounding drywall. Ive looked up the meter he used and it has different settings for different materials. He never changed the setting between drywall and subfloor. Could he have purposely skewed the readings to benefit his company?
Unless the pin meters are a quality, calibrated pin meter, you cannot know for sure what quality of results you are getting.
Regarding the maintenance personnel meter, you really do generally need a specific setting for the material you are measuring. Putting his finger across the pins is not the way to check a meter’s viability.
NOTE: Wagner does not manufacture pin-type moisture meters.
i use a moisture meter to get general readings of moisture in different building materials.
what do you recommend as a general purpose moisture meter for this use?
Bruce,
If you are just trying to get ‘relative’ moisture readings (rather than absolute; I assume that is what you meant by ‘general readings’), then every Orion model has a Relative setting that you can use. I would recommend the Model 950 if you are in the Restoration or Inspection field.
For solid wood, every Orion has the capability to provide absolute Moisture Content (MC) % values. We do provide a few settings for non-solid wood-based materials to also provide absolute MC% values.