Engineered hardwood flooring is designed to minimize gaps due to expansion and contraction of the wood, but it’s not uncommon to find gaps in such materials, and the reasons are many, so it’s important to find the source of the problem in order to fix it. Let’s take a look on Engineered Wood Flooring gaps!
It is important to understand the behavior of regular wood and engineered wood during the expansion and contraction periods, in order to detect the problem.
“Normal” wood expands and contracts with changes in humidity. It swells in high humidity and shrinks in low humidity. The amount of expansion and contraction largely depends on the orientation of the wood grain. Wood moves mostly across the grain rather than with the grain. Traditional hardwood flooring boards (and the top layer of engineered floors) are cut parallel to the grain. As a result, the boards tend to get wider and narrower (across the grain) more than they get longer and shorter (with the grain).
Engineered flooring essentially consists of a hardwood top layer applied over a plywood base. Plywood is assembled in layers using a technique called cross-graining, and the grain of each layer is perpendicular to the grain of the layers above and below. As one layer wants to expand or contract side to side, the neighboring layers want to move front to back. Thus, the layers work against one another during the expansion and contraction process, with minimal results. This is the main reason engineered flooring is most of the times immune to the regular wood behavior on expansion and contraction.
Gaping Due to Humidity
Like mentioned above, the plywood core of engineered flooring helps reduce gaping due to natural expansion and contraction, but it doesn’t always eliminate it. That explains why humidity is a very common cause of gaping in engineered flooring. It’s also why installers should acclimate the flooring before installing it.
One of the common solutions suggested for this problem is to carefully “condition” your home year-round to maintain ideal humidity levels. The idea is to run an air conditioner to lower humidity in summer and run a humidifier to raise it in winter. Although considered by many an environmentally irresponsible approach, this is the only possible way to prevent excessive humidity to damage the engineered wood floor via gaping.
Gaps Related to Installation
Engineered hardwood flooring can be nailed down, glued down, or “floated” (read our articles on floating floors). In all cases, the floorboards must be fitted tightly together during the initial installation. If they are not installed like that, the gaps stay there for good, specially if they shrink during the periods of higher humidity, that’s when the flaws become real apparent.
If your choice was for glue-down flooring, an experienced installer must make sure that the boards are fitted together properly the adhesive glue begins to set. If there are any gaps after the glue dries, it becomes really hard to correct the gaps. Even if the installer comes afterwards and “fixes” gaps, trying to close them, it might seem that they got fixed initially, but the adhesive used for glue-down floors, has a “memory” that can pull the boards back to the original position they were glued in. therefore the gaps open again.
Most people that want to do the flooring themselves will pick a floating floor installation, since it mostly involves clicking wood planks together to form a brand new wood surface, laying it over an underlayment foam pad. The best way to prevent gaping with this installation is to cut the boards the right size and to click them together properly, making sure there is no gaping with each board before moving to the next one.
With all types of installation, flooring manufacturers unanimously recommend acclimating the flooring for several days by laying out the material in the room where it will be installed. This allows the wood to adjust to the ambient humidity and temperature in the room before the flooring is installed. If an installer fails to acclimate the material, there’s a potential for greater wood movement after the boards are installed.
Gaps Due to Material Flaws
The engineered construction of engineered flooring helps minimize the effect of natural flaws in wood, but it’s still wood, and wood being a natural product, it has natural flaws that inherent of the material. As a result, some boards won’t fit together perfectly. If a gap shows up when you’re installing the flooring, try to find a board that fits better. Otherwise, if the gap is left on the floor, the only solution is to replace the board or to fill the gap with a color-matched wood filler.