Don’t let this happen to your new hardwood floor (Avoid floor failure)

I am called in to inspect probably twenty to thirty hardwood floors each year that, after several weeks or months, have begun to open up. A quick reminder: solid wood floor planks are each one piece of wood, while engineered wood planks are several different layers of wood glued together, much like plywood. From time to time I see an engineered wood with gaps. In any case, it is a serious problem and very expensive. If you take the time to read the rest of this article, you can be sure this won’t happen to you, I promise.

“Moisture levels” are very important with solid wood flooring. All wood has a certain amount of moisture. When solid wood flooring has been installed, especially if it has been nailed or stapled, and then begins to open up at the joints so that there is a gap between adjacent boards, it is because they have shrunk. The only other possibility is that your house has been expanded, but I’m pretty sure that never happened and never will. So why did the boards shrink? Because they lost moisture since they were installed. When wood dries it contracts, when it gets wet it expands. Ok, now we are getting to the most important part.

Most people are familiar with the term “acclimatization”. Most people know that wooden floors, even laminate floors (such as Pergo), need to be acclimatized before they are installed. Usually the instructions say to acclimate for 48 hours, or 3 days, or whatever, and then install. THAT IS NOT RIGHT. If you acclimate the product as directed by the manufacturer for the appropriate time, then install it, and then open it, the manufacturer will not guarantee or replace it. The fine print in flooring installation is this: When the installer installs flooring, they agree that the flooring and subfloor are suitable for the installation. The problem is that sometimes hardwood flooring appears in the house to be acclimatized to a 15% moisture level and needs to be installed in a house with a 6-9% moisture level subfloor. There is no way the floor can acclimate to those conditions in a few days. It will still be too wet. And after you install it, it will shrink and cause gaps. And worst of all, the flooring will have to be ripped out and disposed of. It is not a correct situation.

I need to insert a small point here. “Some” gaps in hardwood floors are very normal, especially if you live in an area with real seasonal changes like I do in Eastern Washington. Our homes here will invariably be drier in the winter and wetter in the summer, which will cause some minor gaps and is perfectly normal. A sure way to tell if the gap is normal is if it disappears each year during the wettest season. But the gapping I’m talking about is not like that. A lady showed me how some spaghetti that had fallen on the floor had rolled through the holes. Or if you’re missing one or more of your favorite pets, that’s also a clue.

THE SOLUTION So before this horrible scenario happens, be sure to do the following before installing your new flooring. The soil should be checked for moisture with a wood meter. There are pin (invasive) and magnetic (non-invasive) meters, either of which will work. However, these cost between $200 and $300 or more. Insist that the installer have the moisture checked, especially since it will be a BIG problem for the installer if you have gaps later. Because you know what is going to happen? The manufacturer will send me to look at the floor, I will take many measurements of dimensions and moisture levels, and using the coefficient of dimensional change tables in the Wood Handbook, I will be able to determine what the actual moisture level of the wood was at the time of installation I will find that it was too high (or MUCH too high), and the finding will be that the wood floor was not acclimated to the normal environment of the house before it was installed. OH! That will cost someone a lot of money, and it will cost you at least a lot of hassle with replacement, etc. You don’t want that, and neither do I.

By the way, engineered wood definitely needs to be acclimated as well, although some of the manufacturers don’t want the boxes to open for acclimation and some do, so pay attention to that. Also, laminates (which are real layers of wood similar to engineered except for the top layer which is melamine (aluminum oxide or similar) must also be weathered, but I have never seen a claim denied because the floor was not weathered. Generally laminates and many engineered woods are “floating”, meaning they connect together and become a single unit Any dimensional change does not normally cause gaps, but rather a change in the amount of gap free (perimeter expansion space) in the walls.I will cover these topics in another article.

IN SUMMARY: With any type of wood flooring, but especially solid wood, make sure the moisture levels of the wood are between 2% and 4% of the subfloor the flooring will be placed on. In my part of the country where the relative humidity of houses is usually between 25% and 40%, the flooring needs to be between 6% and 9% before it is installed. That leads to one of my favorite phrases, “IMAGINE WITHOUT GAPPING!”.