A moisture meter is handy tool that aids in the meaurement of moisture in construction materials. It is most commonly used with wood, but can also be utilized with concrete and sheetrock. Measuring moisture in a particular material is important, as it can save a lot of hassle and problems later on.
The type of moisture meters used most often are pin and pinless. (Learn more about the differences by reading our previous blog Moisture Meter: Pin vs. Pinless) Newer versions of the tool provide an LCD screen for easy reading. Pin type meters work by passing a current between the first pin and the second pin. The strength of the current indicates the amount of moisture in the material, as moisture acts as a conductor. A pinless meter will send a wave of electrical signal into the material, which creates a field. The amount of moisture present will have an effect on the field. It should be noted that pinless meters can give inaccurate readings if there is too much moisture on the surface.
In wood, a moisture content above 20 percent can indicate a water problem, that may lead to damage later on. This can include cracking, shrinking or other changes in shape. Too much moisture in any material can be a breeding ground for mold and will weaken the material overall, which can cause serious accidents. The majority of contractors aim for an eight percent moisture reading. This can vary as high as 11 percent along the coast of California and the southern United States, to as low as six percent in desert climates such as Nevada and Arizona.
Any responsible contractor will use a moisture meter through all phases of a project to keep results consistent. This is especially important with wood projects, as wood is most prone to changes when the moisture content is not right. Any material should have the proper moisture content for the environment in which it will be used.