Wood flooring problems are usually unexpected and most often preventable. Wood flooring is the real thing, unlike laminate which is a photograph of wood. Being a product of nature there will be occasional wood flooring problems. Wood flooring problems will usually be prevented through proper milling, installation and care once it has been installed. The information in this article also pertains to bamboo flooring.
Most Common Wood Flooring Problems
Wood floor problems caused by moisture are usually avoidable. Moisture is woods best friend and woods worst enemy. Both excessive moisture and too little moisture result in more wood, bamboo and laminate flooring problems than any other cause. It is a natural characteristic of wood to expand as it takes on moisture and to contract as it looses moisture. Therefore it becomes imperative that wood flooring is milled to a suitable moisture level and acclimated into the environment in which it is to be installed. Once installed, the environment needs to be controlled to prevent excess gain of moisture and excessive loss of moisture. Wood flooring expands when its moisture content increases and contracts when its moisture content decreases. Wood flooring also expands and contracts with an increase or decrease in temperature and relative humidity, requiring that the environment also be controlled for proper performance.
Wood Flooring Problems from Excessive Moisture
Cupping, buckling, and crowning are three common excessive moisture related wood flooring problems. encountered in wood flooring.
Cupping
Cupping occurs when the moisture content of the bottom surface of the flooring is greater than the moisture content at the face of the boards. The excess moisture at the back of the board works its way to the surface and as it moves through the board the floor develops higher edges giving it a cupped appearance. Some cupping is normal especially with wider boards and not considered a wood flooring problem.
Crowning
Crowning is the reverse of cupping. Crowning occurs when the moisture content at the face of the board is greater than the moisture content of the bottom surface. With crowning the centers of the boards become distorted upwardly so that it is higher than the edges of the board.
Crowning is most frequently the result of improper repairing of a cupped floor. This occurs when a cupped floor is sanded prior to obtaining the proper moisture level for the environment in which it is installed. During the repair of the cupped floor the surface of the boards are sanded flat. If the moisture level was still elevated at the time of sanding, as the floor dries to its proper moisture content the floor will develop a crowned surface.
Buckling -Tenting
Buckling is a wood flooring problem caused by excessive site related moisture. There are a number of moisture related causes that will cause buckling flooring problems. While flooding is a more obvious problem, buckling can also occur from a wet slab, pipe leaks, excessive airborne moisture, a house that is left vacant without the HVAC system operational. With buckling, if a floor was not properly installed such as the proper adhesive used or adequate nailing or stapling, the problem of buckling can be exacerbated.
Tenting and buckling are often used synonymously as the same wood flooring problem. Buckling and tenting are the result of excessive moisture. Tenting is more often seen with a floating floor where an increase in moisture has causes it to expand. If there is not enough space around the perimeter of the installation the floor has no where to go so it tents upward. The wood flooring problem of tenting can be avoided by allowing for proper expansion of a wood floor both floating and one installed with fasteners. While tenting without extremely high moisture is more common with a floating wood floor than one that is fastened down, it can occur with all types of installations of wood, bamboo and laminate flooring. Wood flooring grows the most in width than length. Flooring manufacturers and the National Wood Flooring Association advise that a gap should be left around the perimeter of the room and at all fixed objects to allow for this expansion. With every floor the manufacturers installation standards should be checked for the recommended expansion gap size.
Delamination
Delamination in an engineered wood floor product is the separation of its layers. Usually the veneer (top layer) has separated from the core plies. Delamination one of those wood flooring problems that is often moisture related. The cause is usually flooding, a plumbing leak, refrigerator ice-maker or other site related moisture intrusion problem. Delamination can also occur from humidity that fluctuates between extreme.
Wood Flooring Problems from Too Little Moisture
Shrinkage
What is seen as shrinkage may or may not be actual shrinkage. Just because you have gaps between boards does not mean they have shrunk. (see gaps). When boards are installed with a moisture content that is greater than what it should be under normal living conditions, the boards may contract to their normal width and leave gaps though the boards have not shrunk. When a floating floor is locked in the boards may move leaving gaps at points of stress, this is not actual shrinkage. When the width of the board contracts to the point that it is narrower than the width it was manufactured at and remains at the narrower width during seasonal change, this is shrinkage.
Gaps
Gaps are not always considered to be wood flooring problems. Normal seasonal gaps with wood flooring occur with changes in relative humidity. When the relative humidity drops especially during the heating season, gaps will develop unless the relative humidity is controlled. Once out of the heating season the gaps should close back up as the relative humidity increases.
Abnormal gaps are gaps that remain with seasonal change. There are many causes for abnormal gaps from manufacturing, to installation and site related gaps. When boards are exposed to extreme moisture they may grow and crush and once the boards dry you will have gaps. When flooring is installed with too high of a moisture content or there was too high of a moisture content in the subfloor, gaps may develop as the wood dries. Other causes can include problems such as debris between boards, improper nailing or gluing, foundation settlement and problems such as excessive heat from heating ducts or appliances.
Checks
Checks are a low moisture related problem. The separation of the wood is almost always seen across or through the annual rings. The loss of moisture may be a manufacturing related concern that occurred with the loss of moisture during drying. Checking can also be an environmental concern that occurred during storage or after the floor was installed.
Checking
Checking is long lengthwise cracks in the veneer layer of an engineered wood floor. As with checks, checking can occur when the wood is manufactured at moisture levels that are not compatible with the environment in which it is installed. It can also occur with environmental conditions such as excessively low relative humidity following installation.
While we have addressed the more common wood flooring problems there are many others. If you experience wood flooring problems you may wish to engage the services of a National Wood Flooring Association Certified Flooring Inspector such as the Weinheimer Group.