Moisture causes ongoing buckling of floor boards
Humidity, leaks can be culprits, but floor may also have been installed incorrectly
A how-to guru advises a reader on who or what may be at fault if a home’s floor boards are buckling again.
Q In June 2017, part of the flooring that had been laid two years earlier in my house had to be removed and reinstalled because of flooding from a broken washing machine. In October, I had to call the vendor because some of the boards had buckled. A worker repaired the problem by loosening some of the boards.
Last month, the problem reappeared in worse form. The vendor told me that if the humidity in my home is higher than 55 per cent, I would have to pay for new flooring and labour. He brought a humidity meter, and in the wet weather the reading was above 70 per cent. Most of the flooring looks fine except where there is buckling, which appears to be caused by the boards being laid too tightly. Am I justified in concluding that the floor-laying in June was faulty and that the company should fix the job?
A Call a different wood-flooring contractor and ask for an inspection and an estimate of how much it would cost to fix the problem. Once you learn the likely cause(s), you can decide whether to go back to the initial installer to demand a fix if the problem is indeed how the flooring was installed. Or if the problem is something else — such as a new leak — you’d know that you need to pay to have the floors fixed. Then it would be only fair to hire the company that did the inspection.
Rusty Swindoll, technical services manager for the National Wood Flooring Association (nwfa.org), looked at the pictures and said his best guess is that there is a fresh leak of some sort from the washing machine, the nearby hot-water heater, or where water is piped to or from these appliances.
Humid air can indeed cause problems with wood flooring, Swindoll said, but if that were the only issue, you’d see what the flooring industry calls cupping. Edges of the boards rise and the centres sink, giving the floors a striped texture.
The boards on your floors look flat, except where they have bulged. So, besides a leak, there might be a few other issues. The boards might not have been fastened securely, or the installer might have failed to provide the required expansion gap where the flooring meets the walls. Boards should be installed to sit tightly together, but there needs to be a gap at the edges so that the wood can swell a bit in humid weather. The required gap depends on whether the flooring is solid wood or “engineered flooring,” which is made up of layers of wood or composite material. The pictures you sent show you have an engineered product, which means the gap width should equal the thickness of the boards, Swindoll said. So, if your flooring is fiveeighths-inch thick, the flooring would need to stop that distance from the walls.
Installers use baseboards or a piece of moulding attached to the lower edge of the baseboards to cover the gap. But if the moulding is nailed to the floors, the nails defeat the purpose of the gap, which could also be the problem.
Although engineered flooring can be distorted permanently if soaked, it is more forgiving of swings in humidity than solid-wood flooring, Swindoll said. Manufacturers generally specify that a house with engineered wood floors needs to be kept at 60 to 80 F (about 15 to 27 C) with relative humidity between 35 and 55 per cent.
To the extent that high humidity in wet weather is a factor, you (not a flooring installer) would be responsible for addressing that through the use of a dehumidifier and a humidifier, depending on the season. But no one should assume that high humidity is the only culprit until all of the possibilities are checked out.
To find a trained contractor, you can use the “find a professional” service on the flooring association’s consumer-facing website, Woodfloors.org.
If seeking help from a different contractor still leaves you feeling as if you are being taken advantage of and you want to pursue legal action, hire a flooring inspector who can testify on your behalf. The flooring association also has a “find an inspector” feature. But you will need to pay the inspector for the diagnosis; flooring contractors generally bundle their cost for doing the inspection into the cost of fixing the problem.
Wooden flooring — hardwood or engineered — needs to be installed with a gap at the walls to allow for expansion due to humidity.