A newly axed tree won’t gush out a flood of water when it hits the ground, but about 200% of that tree’s current weight is due to moisture. By the time that tree turns into a hardwood plank finding its way to your living room subfloor, that moisture content is only around 6%. Moisture affects wood from the time it is first run through the sharp rough edges of a saw and all the way through the fine-tuning milling and machining process. Moisture plays a part in storage, delivery and even installation. Once your hardwood floor is completely installed in your home, that tree will still be hanging on to a percentage of its moisture content – and as long as there is moisture in the air it isn’t going to let it go.
Moisture isn’t a bad thing, and obviously we need air and water to survive. But when it comes to hardwood floors, there is such a thing as “too much of a good thing” – and that good thing is moisture. It might be good for garden, but it’s not good for your indoor hardwood floor. Moisture causes hardwood floors to expand and contract – which is seasonally acceptable – but too much moisture, and your hardwood floors will have noticeable gaps, crowns, irregularities and even buckling that will affect the floors appearance and structural integrity. Excessive moisture can lead to floor rot, particularly if the floor is not properly finished and protected.
Household hardwood floors should have a moisture content between 6% and 9%, but the percentage will be affected by the type of wood, the weight of the wood, and many other factors. Some woods naturally have more extreme moisture contents, ranging from 4% to 18%, but oak floors are generally in the 6% to 9% range. The percentage of moisture content is simply determined by comparing how much moisture is in solid wood compared to the same weight of oven-dried wood. Before the wood is installed in your home, its moisture content should be tested with a moisture meter to make sure it is within an acceptable range.
Controlling the temperature of your home is the best way to prevent unwanted gaping and floor movement throughout the seasons. Keeping the indoor humidity levels at a range between 30% and 50%, and a room temperature between 60 degrees and 80 degrees Fahrenheit is an easy way for you keep your floor’s moisture level at a healthy, stable level. But there are also measures the manufacturers, delivery companies, and installers can take to keep your hardwood floors from acting moody from their moisture content changes.
To begin with, quartersawn wood will be more stable than plainsawn wood. Quality manufacturers will record moisture levels before the wood even leaves their facility, and will include their moisture-level findings on packaging material. They will also have temperature-controlled storage to maintain a consistent moisture content.
The delivery company should take care not to subject the wood to any extreme temperature changes. Once the wood arrives at the place of installation, the wood should be left out to adjust to the room temperature for at least a couple days before the actual installation. A moisture reading should be taken just prior to installation to make sure that the moisture content of the hardwood is within standards proposed by national flooring associations.
Moisture is a fact of life, and your floor will move – although you might not even notice it. Wide planks move more than smaller wood strips, and you might notice a gap between two wide 5” planks, but hardly the millimeter changes between two 2 ¼ “ hardwood strips. By making sure your hardwood flooring reaches an acceptable moisture level before installation, and by keeping your home at a consistent temperature and humidity level, the natural movement of your hardwood floor will be minimized.
Despite receiving the ax and going through an extreme weight loss, your hardwood floor is still living. It needs to be kept comfortable. By keeping its moisture content stable from beginning to end, you’ll have a strong, solid hardwood floor to support you for the lifetime of your home.