Fixing problems with warped or bowed flooring
A look at some common warping and bowing questions with wooden flooring.
My flooring is warped / bowed before installation
Wood is a natural product and as such a small amount of bowing is to be expected in any wood flooring board. Engineered and solid wood flooring products are produced in controlled conditions and when packaged for distribution should contain moisture content of approximately 8% – 12%. Most installation instructions state that the boards must be acclimatised in the installation environment for a certain amount of time and should not be unwrapped until they are required. The reason for this is to allow the moisture content of the boards to adjust to changes in relative humidity before they are installed, reducing the risk of problems after installation.
Staggering the joints during installation is also necessary to maintain the structural integrity of the floor and eliminate any deformities caused by exposure to moisture. This in turn keeps the flooring flat and fully supported. Bowing to a degree is not considered a defect in a wood floor board, and does not necessarily indicate a faulty product – provided the flooring is installed according to the manufacturer’s instructions it should not affect the quality of the finished floor.
My floor is warping after installation
Cupping and crowning are common complaints that develop with high humidity or moisture levels, both occurring across the width of the wood flooring material. Cupping is when the edges of a board are high and its centre is lower, and it only occurs after water or moisture is absorbed into the wood from beneath, normally from the sub floor. Cupping is caused by a moisture imbalance through the thickness of the wood. The wood is wetter on the bottom of the board than on the top, and hence the bottom expands relative to the top, causing the cupping effect.
The first step in repairing a cupped floor is to identify and eliminate the problem moisture source. Once the source of the moisture is controlled, cupping can usually be cured. The floor may improve on its own as it dries out over time, or alternatively you can try and accelerate the drying process using a dehumidifier. Once the moisture content has stabilized, the floor can then be reassessed.
Crowning is the opposite of cupping, where the centre of a board is higher than the edges. Moisture imbalance is again the cause of the crowning however, the excessive moisture is introduced on the top of the floor and not from beneath, perhaps from spilled water or an appliance leak. The end result and problem solving is the same as cupping – to eliminate the moisture source and dry the floor either naturally or with the aid of a dehumidifier.
Flooring installers should always measure the moisture levels of a subfloor before installation. They should not rely on the age of a concrete slab to determine that it is ready for installation – moisture readings are essential before installation takes place. It is equally important to check the relative air humidity and acclimatise the flooring before installation.
Always follow the flooring installation instructions specific to your flooring to ensure you don’t encounter these problems with your floor.
