The Moisture Factor in Recycled Wood
The idea of reclaimed lumber is an appealing one. Since nobody is using the wood that you spy with your frugal eye – be it an old barn or a gym floor that’s being replaced – you imagine turning it into that long-desired wood floor or ideal piece of furniture in your home. Great idea! The do-it-yourself gurus above nod their approval. Environmentalists bless you. Wood installation contractors may wince at the loss of prospective clientele, but they appreciate your recycled wood project. Wood experts have one thing to say: “Watch out!”
That’s because your dream, as defined, does not account for potential wood moisture problems. It is extremely important to measure the moisture content (MC) of reclaimed wood before manufacturing it into a finished product.
“It has already been resolved.”
Unfortunately, the need for an MC test applies for the wood’s lifetime.
You would be right to assume that manufacturing and installation experts may have run a moisture meter over the wood prior to its initial building application (barn or previous wood floor). However, recyclers must keep in mind the same warnings that wood installation experts reserve for everyone: first, verify wood MC levels in order to avoid costly and vexing finished product problems.
Even if you have knowledge of such prior resolution, all wood must reach its equilibrium moisture content (EMC) in its new home in order to deliver stable product performance for life. The EMC depends mainly on the relative humidity (RH) and temperature of the surrounding air. Wood moisture levels fluctuate with RH. When the RH goes up, wood absorbs or gains moisture; when RH goes down, wood loses or releases it. This is why a wood moisture meter is an excellent investment for any wood flooring or woodworking enthusiast.
“Why should I measure the MC now?”
There are three main reasons. First, an initial wood MC test tells you the existing state of moisture in the reclaimed wood to determine if the wood is ready to manufacture a wood product.
Secondly, for manufacturing purposes, it can help identify wood pieces that do not have the same or similar MC values, particularly if the reclaimed wood comes from a variety of sources. You can then separate the wood into similar MC values for manufacturing and installation purposes.
Thirdly, installers may find that the finished wood product, reclaimed wood flooring, for example, has not reached the correct EMC to ensure that the flooring will not fail after installation. The installer can monitor the MC of the wood flooring until it is at the correct EMC for safe installation purposes.
Also, by measuring each reclaimed wood piece with a moisture meter, you can get a visual indication of the presence of wood defects, such as knots. If these issues were not fully addressed and resolved by the wood’s first owners, reclamation may include some wood rehabilitation costs.
In the event of moisture saturation, a wood moisture meter can make the difference between the end wood products success and failure. Moisture problems that remain unresolved can jeopardize your project and lead to cracks, splits, shrinkage, gluing failures, cupped or curved panels or other moisture-related problems. But the good news is a simple MC check helps to pinpoint where your moisture-related problems are so that they can be resolved previous and during the manufacturing process.
“Will MC be a continuous worry?”
Not necessarily. All wood species contain varying levels of moisture within their cells. When the wood has sufficient time for its moisture levels to stabilize with the RH and temperature of its environment, the wood has reached EMC: its moisture balance.
Optimally, the reclaimed wood must reach its EMC in its new home. This is especially important if you are manufacturing wood flooring as almost every wood floor will endure some expansion and contraction as seasons and RH levels change.
A simple moisture meter test allows users to measure the MC across an entire wood surface. Once EMC is reached, consumers can monitor the woods MC as needed to pre-empt potential moisture-related problems in the future.
Wagner Meters has designed a diverse line of wood moisture meter products for moisture management of all wood species. Wagner Meters uses pin-less, electromagnetic wave technology to provide precise, immediate MC measurement on the spot. The Orion® wood moisture meter product lines carry the exclusive Wagner Meters seven-year warranty. Also, the Orion 940 and 950 can store MC spot-check results, so installers can record and monitor the woods high, low and average MC for future reference.
Wagner Meters state-of-the-art design makes wood moisture measurement an exercise in hand-held convenience, precision, and frugality. Consider the modest investment in a Wagner wood moisture meter to ensure that your reclaimed wood project lives up to your performance expectations.
Tony Morgan is a senior technician for Wagner Meters, where he serves on a team for product testing, development, and also customer service and training for moisture measurement products. Along with 19 years field experience for a number of electronics companies, Tony holds a B.A. in Management and his AAS in Electronics Technology.
Last updated on February 25th, 2020