Diagnosing the Cause Of, and Avoiding Cupping in Solid Wood Flooring
Cupping or dishing in solid hardwood means the boards raise slightly at their edges making the hardwood flooring uneven across its width. The cause of cupping is an imbalance of moisture through the timber. This can be a result of a spillage on the floor, or because of the hardwood flooring gaining moisture from the sub-floor material.
Taking moisture reading of the underside of the timber and comparing this with a reading taken from the upper side will confirm this.
Wood normally expands when it takes on moisture. It therefore follows that moisture on the underside of the wood will make the underside expand laterally. However, the upper side of the wood which has not absorbed any moisture, so this stays at near its original size. The immense strength of the expansion of the underside of the wood causes the edges of the wood curl.
On nearly every incidence …