When it comes to the moisture content of wood flooring, ignorance is NOT bliss.
Wood is extremely sensitive to its surrounding environment. If you’re not paying attention, your wood flooring could contain too much moisture at the time it’s being installed. And this could easily lead to a catastrophic flooring failure due to various issues such as buckling, cupping, crowning, cracking, mold, or mildew.
Why is wood moisture content important?
If at the time of installation, the moisture content of the wood is out of whack with the surroundings, it could spell disaster for your floor.
Needless to say, no one wants a wood floor to fail. However, the risk of some sort of problem is high if you don’t assess the wood’s moisture content (MC) before, during, and even after the floor installation. That’s because wood is a hygroscopic material, meaning that it will absorb or release moisture depending on ambient conditions.
Wood tends to absorb moisture in wet or humid conditions, and when it does, it expands. Conversely, wood tends to release moisture if the air is dry, and this causes the wood to shrink.
If the process of expanding or shrinking is severe enough, you may end up with an uneven floor surface. Or perhaps you’ll start to notice significant cracking or separation of floorboards. Unless you undertake remedial measures, which are often quite costly and time-consuming to perform, the floor may never recover. It’s likely that it will always look unsightly or—even worse—it may become a potential tripping hazard.
Obviously, that’s no good. So now for the good news: The old saying, “An ounce of prevention is worth a pound of cure,” holds true in the case of wood flooring.
Moisture measurement in wood flooring
All that’s needed is to use a high-quality, non-damaging pinless moisture meter to take quick-and-easy measurements of the MC of the wood planks. The flooring professional will want to do this soon after the wood arrives at the location where it is to be installed. And then continue monitoring the MC while the wood is acclimating to its new surroundings.
The aim is for the wood to reach an equilibrium state where it is neither absorbing nor releasing moisture. Once this happens, we say that the wood has reached its Equilibrium Moisture Content (EMC), expressed as a percentage MC based on the ambient temperature and relative humidity.
Before installing any wood flooring, the wood must have already reached its EMC in the location where it will be permanently installed. Although the EMC will vary depending on ambient conditions, typically you’re looking for a wood MC of about 6 to 9%. Failure to allow the wood to acclimate properly could result in a flooring failure if the wood shrinks or expands after the flooring has been installed.
Why a quality wood moisture meter matters
Every flooring professional or contractor should have an accurate wood moisture meter. It’s the only tool that will let you know if the wood flooring has reached its EMC and is ready to be installed. And not just any moisture meter will do. It’s important to use a meter that gives accurate measurements and is properly calibrated for the types of wood flooring that will be installed.
It’s also important to have a meter that can measure in the 5 to 6% range. Many meters do not read this low or don’t give accurate readings at low MC. That won’t do for anyone who installs wood floors. Using a quality wood moisture meter ensures quality work and protects the installer’s professional reputation.
Pin vs pinless moisture meters
Generally speaking, the flooring professional must choose between two types of wood moisture meters: pin and pinless. A non-damaging pinless meter uses electromagnetic waves to scan for moisture, while a pin meter measures the electrical resistance between two metal probes inserted into the wood.
The choice between pin and pinless is quite simple for anyone who installs wood floors. That’s because pinless meters are 100% non-damaging. Unlike pin meters, they don’t require the insertion of metal pins that mar the appearance of the wood.
Non-damaging pinless meters have other significant advantages. Most notable is the fact that they are a big time-saver. You can scan many board feet in just seconds. Taking multiple moisture readings of hardwoods with a pin-type meter can be time-consuming and frustrating. For dense wood, such as oak or hickory, proper insertion of the pins is challenging. This means you risk inaccurate measurements, defeating the whole purpose of using a moisture meter.
Remember this one thing
In a nutshell, remember this: unlike many other types of flooring, wood is highly sensitive to its environment. If you’re a wood flooring professional, you’ll need a fast, reliable way to measure wood’s moisture content. The only way to do that is to use a quality, non-damaging pinless moisture meter that consistently gives you accurate readings.
Previously published in Premier Flooring Retailer