Checking Moisture content in Subfloors

1 Checking Moisture content in Subfloors

Determining moisture content is essential for quality control within the engineered timber
flooring installation process. Laminate timber flooring installers must know the moisture content
of the wood flooring and the subfloor.
We are at a time when humidity levels are very high. In homes minus climate control (new or
existing houses), these high humidity levels will elevate the wood subfloors' moisture level,
which can impact newly installed wood floor boards.
Irrelevant to what type of engineered timber flooring he is installing, every installer should have
a meter for inspecting wood subfloors. Moisture meters have culminated into the most crucial
tool for flooring installer, but it is probably the most neglected tool in the industry. Continuing to
work without a moisture meter increases your chance of failure. The wood floor boards installers
and moisture Meters can also be employed by all flooring trades. Moisture Meters can be
utilized to check subfloors for water crevasses, moisture content of wood subfloors before
establishing any flooring, and if the hardwood is at the right tier for the subfloor.
1.1 There are two kinds of Moisture Meters for wood subfloors:
1.1.1 Pin or Invasive: This is the older of the two. The pins measure electrical
resistance across opposite sides of the pins inserted into the wooden product.
Generally, pin meters will measure from 6% to 30%. This testing method was
developed to measure timber's moisture content but is arguably problematic for
large areas of walls and polished timber floors where pinholes may be unsightly,
especially in materials such as drywall and on solid surfaces where the pins
cannot infiltrate.
1.1.2 Pinless or Non-Invasive: This meter can effortlessly be moved across the floor
to identify wet areas or a wet subfloor and is not influenced by temperature and
rough surfaces. Pinless or Non-Invasive meters will also calculate from 6 – 30%.

Bearing a reading from the surface of such materials can be tricky, as the surface may be dry
owing to low humidity. Nevertheless, below the surface, the material or substrate may be wet.
Non-invasive moisture meters that operate on the principle of impedance measurement
employing direct contact electrodes have been adapted to the requirements of various
industries over the years. Direct contact electrodes present more accurate results, versatility,

Page 4 of 2
the profundity of signal penetration, and reproducibility of readings than other Non-invasive
moisture meters.
When the wood subfloor takes on extra moisture, it expands. The flooring will shift, buckle, or
cause joint show-through with this expansion. Loose-Lay flooring established in new
construction during the hot, humid summer months typically has some failure during the first
heating season. The flooring is established when the subfloor has picked up the extreme
moisture and swelled. The flooring supplies some expansion space and looks good for a few
months. The heat is turned on in October/early November, and the drying procedure of the
subfloor starts. The subfloor dries out, shrinking, and the once good evolution zone gets tighter.
The subfloor resumes to dry, and the engineered timber flooring begins to buckle because the
fullness created by the subfloor shrinkage now has nowhere to proceed.
Engineered timber flooring over crawl rooms has been a problem since the beginning. Every
wood subfloor beyond a crawl space should be tried for moisture. The crawl space should also
be reviewed for a minimum of 6 mil black poly blanketed in stone overlapped and running up the
walls. The minimum height for a crawl space is 18″ elevated and should have vents or a
dehumidification system. If the room is not vented, the excess moisture is entrapped, and the
dry subfloor will pick up this moisture and cause flooring problems. If the humidity is not
controlled in the crawl space, this will compel the subfloor to go through a lot of up and down
transitions leading to a engineered timber flooring failure.

Related Blog Posts

Solid Wood Vs Engineered Wood Flooring – Which Should You Choose?

Solid Wood Flooring Typically crafted from a hardwood species, such as oak, maple, or walnut, solid wood flooring, as the name suggests, is made completely from a single, solid piece of wood. Solid wood flooring can be sanded and refinished several times over its life, however it is prone to warping in humid or damp conditions.Engineered Wood FlooringSimilar in appearance to solid wood, the construction of these boards features multiple sheets of thin hardwood bonded together over a premium base material. This construction provides excellent resistance to warping and a long lifespan of around 25 to 30 years with proper care and maintenance.

Read More


About 'DIY' InstallationWhen people consider DIY floating floor installation, it is usually due to budget restraints. While they don’t necessarily save on the cost of materials, they believe they are saving a significant amount on labour costs. These days, you can quite easily search for tutorial videos online about anything, and floorboard installation is no different. The problem with these videos is that they often make the task look easier than it really is, advise incorrect techniques or use improper adhesives and tools that will result in an extremely inferior finish. What may seem to be a relatively easy, cost effective and self-rewarding task, usually ends up more time consuming and more expensive in the long run.

Read More


Q: What is my best option; am l better off buying a 14mm (Overlay) or 19mm (Traditional) hardwood floor?A. It is obviously personal preference and each job has different requirement; a 14mm floor board in our (Overlay Range) can be sanded the same amount of time as a 19mm floorboard it comes in a shorter random spread which is easier to manage on the job site and has been designed to go over a flat solid surface which is classified as a non-structural floor and in most cases is a better option than 19mm due to less core moisture in the product, therefore a more stable option. On the other hand, a 19mm floor board (Traditional Range) has been designed to go over floor joist which is classified as a structural floor. A 19mm floor board has the same ware layer as a 14mm floor board; it also has a longer average length spread however dependent on your circumstances the choice is yours.

Read More

Whether you are building a new home or renovating, we can help you create your dream living space.

Contact Us today