How to Measure Moisture in Hardwood Flooring
To prevent moisture-related damage or warping, it’s best to use a reliable moisture meter to detect the amount of moisture in wood flooring materials before beginning the installation. You’ll want to take multiple readings with a pin-type or pinless moisture meter.
This preliminary moisture testing tells you whether or not the floorboards are truly ready for installation.
So let’s go over the proper use of wood moisture meters and how to decide on your next steps, based on the readings you get.
As a bonus, you’ll also learn how to select the best meter for measuring hardwood flooring.
We’ll explain:
- Why it’s necessary to measure wood moisture content
- How to take moisture readings on wood floorboards
- The best meter to use for hardwood flooring
Let’s start by examining why measuring moisture makes such a big difference.
Why should you measure wood with a moisture meter?
Flooring installers need to know the moisture content (MC) of their floorboards to determine when they are stable enough to begin the flooring installation.
What do we mean by “stable”?
Wood is a hygroscopic material, meaning it will continually absorb or release moisture—causing it to shift, swell, or shrink—until it has adjusted to the humidity level of its surroundings, or equilibrium moisture content (EMC).
So the wood is stable when it’s done moving or shifting and has reached EMC.
If installers nail or glue the wood down before it’s finished shrinking or swelling, the floor could end up warping, buckling, crowning, gapping, or cupping. Clients might also complain about squeaky or sinking areas of their new floors.
And in a business where client satisfaction is everything, you don’t want unhappy customers spreading word of faulty floors or botched installations and harming your hard-earned reputation as a professional floor installer.
This is why it’s crucial for flooring installers to know:
- What moisture level the flooring needs to reach (the EMC for the area)
- How to correctly determine whether their floor has reached that target moisture content
So let’s cover how to properly use wood moisture meters when installing hardwood floors.
How do you measure moisture content in wood floors?
Follow these steps to get the most accurate, helpful MC readings from your meter.
Step 1: Check meter calibration
The first thing you want to do is make sure that your meter is properly calibrated. Otherwise, all your readings will be skewed even if you’re taking measurements correctly.
While moisture meters should come factory-calibrated, it’s important to check the meter’s calibration before using it for the first time. You may also want to verify calibration if your meter has not been used for a long time, or if it might have been dropped, shaken, or forcibly bumped.
Some meters come with a calibration verification reference device you can use to verify the calibration of your meter. Many meter manufacturers will also recalibrate your meter for you if you have any doubts.
Once you do that, you’ll be ready to take a reading.
Step 2: Determine your target moisture content
Generally, the target MC of most hardwood floors is around 6-9%.
However, the correct moisture range could also depend on your environment and the kind of floor you’re working with.
EMC can vary depending on the climate of the area. (Here’s a chart that breaks down the EMC of different regions in the United States.)
Beyond this, your flooring material may have specific requirements. Always check the manufacturer’s guidelines to see what moisture levels they recommend.
Ultimately, you’ll want to follow manufacturer guidelines when determining your target MC.
Step 3: Taking moisture readings
Before we talk about how to take a reading, let’s talk about when you should take it.
If you’re buying or picking up floorboards for your client, it’s important to bring a moisture meter to ensure the wood you purchase is at a suitable moisture level. By checking the moisture level of your floors at the store, you can select wood that’s closest to your target moisture level, meaning you won’t need to allow for as much additional acclimation time.
Once the flooring is in your possession, you’ll want to keep testing the moisture of your floorboards until you can confirm that they’ve fully acclimated. (You’ll also want to check the wood subfloor to make sure it doesn’t have high moisture levels that could harm your flooring materials when you install on top of it.)
Then you can begin the installation.
The last point you might want to check moisture levels is before you apply finish to the flooring. You’ll want to verify that the flooring is at the moisture level appropriate for applying finishes, stains, etc., according to the manufacturer’s guidelines.
Additionally, you’ll also want to check the flooring’s moisture condition whenever you suspect water damage, humidity changes, or water intrusion from rain, leaks, or spills.
To take a reading:
- Turn the meter on.
- Set your meter to the proper wood species setting.
- If you’re using a pinless wood moisture meter, wipe off any surface water and allow it to dry for 2 minutes, or turn the material over and measure the dry side.
- If you’re using a pin-style meter, you will have to let the surface of the wood dry or use insulated pins.
- For a pinless meter, press the sensor plate firmly on the face of the wood and take a reading.
- If using a pin meter, press the pins into the wood as far as possible to increase the area that’s able to be measured.
- If you experience any problems with your meter, you can use our troubleshooting guide.
Step 4: Sample multiple pieces
Be sure to sample several pieces of your flooring so you can get a more complete understanding of your flooring’s MC. Just one board could have a slightly higher or lower reading than others, so you want to make sure you’re basing your decisions on a larger sampling.
Once you take these readings, you can make informed decisions about the next steps.
Step 5: Proceed according to your moisture readings
If your wood has reached its target moisture level, you can go ahead with the installation.
However, if its MC is too low or too high you’ll want to wait for it to acclimate before installing. You can speed along the acclimation process by:
- Stacking the wood in a way that allows airflow to each piece of wood to help it dry faster.
- Using a dehumidifier or humidifier to lower or raise humidity levels.
- Using a thermo-hygrometer to track ambient temperature and humidity.
Once you do that, you’ll want to check your wood regularly with a moisture meter to determine if it’s reached the right MC.
The best moisture meter for hardwood flooring
Getting accurate readings is all about getting the best, most accurate moisture meters.
First, you have to choose which type of meter you want—pin or pinless.
Each has its uses, but more often than not, pinless meters are the better choice for measuring hardwood floors.
This is because pinless meters:
1) Are designed for smooth surfaces like floorboards
2) Won’t leave behind unsightly pinholes in your client’s floor
3) Can take multiple measurements with speed and ease
Whether you choose pinless or pin moisture meters, the next step is looking for meters that meet quality standards.
You’ll want to find a meter that:
- Is known for its accuracy
- Is consistent
- Provides species correction settings
- Comes with a way to check calibration
- Comes with a warranty
On top of being pinless, our meters meet all of these criteria. They even have a relative measurement mode you can use to take comparative moisture measurements of building materials like drywall and laminate.