The 10 Best Moisture Meters
Special Honors
Flir MR176 While extremely expensive and probably over-equipped for the needs of most users, those who require thermal imaging to help guide them to the source of moisture will find the Flir MR176 to be an invaluable, time-saving tool. It offers the flexibility of pin probes and a pinless sensor. flir.com
Editor's Notes
December 17, 2020:
During this latest update we analyzed our previous recommendations to ensure they were still continuing to prove themselves reliable over time, as well as looked at the various other models available on the market to see if there was anything new worth including. Based on this research, we determined that there was only one model that should be replaced for another. We decided to remove the Tramex MEP in favor of its newest iteration, the Tramex MEP5. While both are very accurate, the latter has a more rugged build and offers Bluetooth functionality, allowing you to connect it with an associated smartphone application for a better visual representation of the results.
April 30, 2019:
Decided to increase the ranking of the Amphenol Thermometrics BLD2000 as it’s value to professional users is apparent. Home inspectors appreciate the clear, sensible way it displays the moisture level: green to indicate it’s in a good range, yellow to indicate it’s too wet, and red to suggest that the water level is high enough that rotting could be an issue.
Also added the Calculated Industries AccuMaster as a versatile, high-value option that can be operated with or without pins. Some users have expressed that the pins could be more durable, but most are impressed with its accuracy and ease of operation. Included the iPower 3-In-1 to provide a model tailored to gardeners; it’s rather basic and can be tough to read due to the small markings on its face, but users seem generally satisfied for the low price.
Had to eliminate the Liumy Detector and the Wagner MMC210 because of availability issues. We replaced the Dr. Meter Tester with the Dr. Meter Intelligent, the latest version of the product. User reports indicate that the new model is an upgrade, with an improved calibration process and the ability to work with a wide range of wood types and thicknesses.
What A Moisture Meter Does
Many have LED indicators that flash green for low or zero moisture, yellow for medium, and red for high.
Moisture meters can be found in the tool belt of any professional construction worker, flooring contractor and anyone else who works with building materials. People working in these professions normally won't begin a job until they've tested the moisture in materials because high levels can lead to structural damage. Excess moisture can cause certain materials to expand, warp, or become brittle over time, and those are only some examples of the problems moisture can cause.
Since moisture is relative to temperature, moisture meters give a percentage moisture content reading. Moisture meters are usually calibrated to wood, so they often have a percentage range of around 5 to 40, but those working with other materials like drywall will need a model with a 0 to 100 percent range. Depending on the model, the meter will either display the reading on an analog scale or digitally. Many have LED indicators that flash green for low or zero moisture, yellow for medium, and red for high. These can be incredibly useful for people who aren't sure exactly what a percentage represents, and whether or not a material is safe to work with.
Some models allow the user to select the material with which they are working, and provide information for that specific one. Pre-loaded materials can include drywall, softwood, masonry, hardwood, cement and more. People who with drywall a lot should get a moisture meter that reads for gypsum, one of the main components of drywall that can completely disintegrate if exposed to moisture. Since temperature can affect a moisture reading, many models have auto temperature correction to ensure an accurate reading. Others are made from materials that are not sensitive to surface moisture, so any condensation on the top of the material being tested will not affect the reading.
Pin Versus Pinless Moisture Meters
There are two main types of moisture meters; pin and pinless. Pin meters contain two metal pins that have to be stuck inside the material being tested. Pinless ones simply need to come in contact with a surface in order to get a reading. These two varieties measure moisture in very different ways.
Pinless meters automatically measure moisture at 1/4 inch below the surface, and 3/4 inch below the surface.
Pin moisture meters work on the electrical resistance principal and measure the electricity flow between the tops of the pins. Since moisture affects this flow, they usually require the user to insert them in several places to get an accurate reading. Pin meters also only measure moisture in the exact portion of the material between the pins.
Pinless meters send electromagnetic signals out of a sensor pad, and can measure the moisture content of several feet of a material in one reading. Those working with cement or concrete usually don't have the option of sticking pins into their material, so they need a pinless meter. But even woodworkers might prefer a pinless model since it won't leave tiny holes in their product. Pin varieties are also prone to breaking, and users needs to keep spare pins on hand.
One might wonder if there is any benefit in using a pin meter, and in fact there is; these models offer variability in the depth of the readings. Pinless meters automatically measure moisture at 1/4 inch below the surface, and 3/4 inch below the surface. Since a person manually inserts the pin variety, they can test the moisture at different depths, which may provide a more accurate reading. Ultimately, getting an accurate reading from either type of moisture meter depends on whether or not the user has properly calibrated it.
The Top Causes Of Moisture Problems
Moisture problems are not to be taken lightly as they can weaken the structure of a home, cause the insulation not to work properly, and even lead to health problems related to mold. Dampness can be brought on by poor ventilation, busted water pipes, roof leaks, and other issues.
Rain can also seep into a home if the weather stripping is old and worn out.
Even if one cannot see mold growing on their walls, if they get a high moisture reading on their meter, there is a good chance that mold has already begun to develop. Rain can also seep into a home if the weather stripping is old and worn out.
Condensation is another top cause of moisture inside of the home. Condensation occurs when warm air cools down, which is why it's important for people who live in hot climates to monitor the temperature and humidity inside of their home. If they allow it to become too warm inside, when the hot air indoors comes in contact with the cooler windows, condensation will stick to the insides of their window panes and cause moisture buildup.
Installing exhaust fans around the house — particularly in high moisture areas like bathrooms — can help prevent hot hair from being trapped inside of a house, which can cause condensation. Those who struggle with burst pipes should use water leak detectors that will alert them to any problems with the plumbing that can cause dampness inside of walls.