The Why, When, and How of Measuring Moisture in Wood Flooring

Measuring the moisture in your wood flooring prior to installation is one of the best things you can do to avoid moisture-related damage in the future. 

That’s why, in this article, we’re going to give you the information you need to know to make wise decisions when it comes to wood moisture. 

If you keep reading, you’ll learn:

• Why you should measure moisture content
• When to measure moisture in wood floors
• How to measure moisture in wood floors
• What to do with moisture meter readings

Let’s get into it!

Why should you measure moisture content with a moisture meter?

Wood is a hygroscopic material, meaning that it will continually absorb or release moisture to adjust to the humidity of its surroundings.

That’s why wood floor planks shrink and swell: they shrink when they lose moisture and swell when they gain moisture. 

This variability is partly why measuring the moisture content (MC) of your wood floors is so important. Avoiding this step means that you might be going into the installation process without proper knowledge of how the wood will react. 

Eventual buckling, crowning, gapping, and cupping are just a few of the issues you can run into if you don’t measure the wood floor’s moisture content. And long-term, clients will probably experience squeaky or sinking floors. This is not only bothersome and costly for the client, but it also harms your reputation as a professional.

Measuring the MC of your floors also gives you the data you need to document how your wood flooring compares to the EMC of the region you’re installing in. 

Put simply, EMC, or equilibrium moisture content, is the point where the wood’s moisture content matches the moisture level of its surroundings. At this point, the wood neither gains nor loses any moisture, which is ideal! The EMC varies depending on the region, and measuring your MC will help you know how close or far you are to reaching EMC. To learn more, you can read our article about EMC and check out this chart that details the different EMCs throughout the country. 

So now that we know the why of measuring moisture content, let’s talk about the when.

When should you measure the moisture content of your wood floors?

The answer here is pretty simple: every time you’re going to do a project with wood floors, you want to measure the wood’s moisture. 

But more specifically, you want to measure at several different stages of the purchasing and installation process. 

During the purchasing process, you want to consider how you are acquiring your wood and measure it then. 

If you are picking your wood up from the lumber yard, you’ll want to take your moisture meter with you. 

Or if you are receiving a big truckload of wood, measure the wood before you unload it to make sure that it’s in an appropriate moisture range. 

No matter where you are acquiring your wood from, keep these few things in mind.

First, know that you can negotiate the moisture range of the wood that you are looking for with the seller. This is a great way to save you time and money later on during the installation process. 

Second, as you measure the MC of wood, especially at the lumber yard prior to purchase, you want to make sure that you are using a pinless moisture meter. You certainly don’t want to be poking a bunch of holes in someone else’s wood!

Lastly, you want a quality meter that will give you consistent and accurate readings. Without accuracy, you can’t know for sure if the wood you are buying is at the proper MC. Having a meter that you can trust is key when taking several MC measurements and buying the wood flooring you need for the job. 

After acquiring the wood flooring and taking an initial measurement, you also want to measure right before it is installed. Then, you know if anything has changed since the delivery to the job site. If something has changed, then you know to look further as to what factors are causing the change, such as the weather. 

Even after the flooring is installed, you want to measure once again before sanding or finishing a floor, especially if some time has passed. 

Why?

Because improper MC  when you begin the sanding and finishing process can impact the end result, for the worse. 

If you have multiple points at which you measure the MC of the wood floor and confirm it’s in the proper range, you can assure your client that you’ve kept up with industry best practices for wood flooring installation, and that’s something you can be proud of. 

How do you measure moisture content in wood floors?

Now, let’s get into the details of measuring the moisture content in wood floors. Follow these steps to get the most accurate and, therefore, most helpful MC readings from your moisture meter. 

Step 1: Check meter calibration

The first thing you want to do in order to begin the MC measurement process is to make sure that your meter is properly calibrated. While every Bessemeter pinless meter comes factory calibrated, exposure to different elements (moisture, dust, intense temperature swings, etc.) might affect the meter’s calibration.

However, by using the calibration verification reference device that comes with your meter, you can easily verify the calibration of your device.

Step 2: Take your reading!

The easiest and most handy step of the process is to take your MC reading. In order to take your reading, simply…

• Turn the meter on.
• Set your meter to the proper wood species setting.
• Wipe off any surface moisture or water and allow to dry for 2 minutes, or turn the material over and measure the dry side if there is moisture on the surface of the wood.
• Make sure the meter’s entire sensor plate is in contact with the wood and press the meter firmly on the face of the wood sample before you take each reading. 

It’s as easy as 1-2-3.

Step 3: Sample a number of pieces

After receiving your wood shipment, you want to sample several pieces so that you can get a general idea about the MC. Just one piece might give you a misleading picture of the average MC of the entire lot of wood. 

Pinless meters like the ones from Bessemeter are especially handy in this case because they allow you to get quick and accurate measurements. If you are able to get a lot of measurements in a short amount of time without leaving pinholes in the wood planks, you can feel more confident about what your next step should be, whether it’s installation or acclimation. 

Keep in mind that these steps will change if you are using a pin moisture meter. Also, if you use a pin moisture meter, you’ll have to make sure that you know the temperature of the wood and how that will impact the reading. Pin moisture meters are very sensitive to temperature, and this could significantly impact the accuracy of your final readings unless you use a correction factor. 

What do you do with your moisture meter meadings?

Now that you have your readings, what do you do with them? 

Here are some things you should consider. 

Whether the wood is already in the environment where it is going to be installed or is going to another location, you want to make sure that the MC of the wood and the EMC of the final location are close to one another. 

If they are not, the wood will have to acclimate until it reaches the proper MC, which can take a long time. If waiting is an option, then stacking the wood properly can help. You can also speed up the process by either reselling the wood and purchasing wood that is closer to the proper MC or by sending it to someone who can dry the wood to the proper MC. 

Having these moisture readings means that you can feel confident that your next decision will be the right one. As you’ve heard, knowledge is power, and that’s the benefit of having a reliable and accurate moisture meter. 

If you want a quality moisture meter at a responsible price point that will make your job easier and give you the data you need, then check out the Bessemeter product page.