This discoloration is due to moisture
These days, many homeowners are opting for wood flooring instead of vinyl, ceramic tile, or marble, and as this may be their first experience with a floor covering material that constantly expands and contracts, they need to be made aware of the problems that may occur with it.

The obvious sources for this important information are the floor covering dealer from whom the homeowner is purchasing the floor, as well as the contractor responsible for its installation. Combined, they should be able to tell the homeowner about the possibility of cracks, how to avoid and/or control them and, in fact, to accept a certain amount of cracking in conjunction with owning a wood floor.

Water intrusion can result in color leaching and discoloration


Cracks can be explained as simply a result of dryness. Of course, moisture, or loss of moisture, is the determining factor of shrinkage. If the wood flooring has been exposed to unusual levels of moisture, cracks will appear when the floor is dried out. Some large cracks are the result of installing wood flooring over sheet vinyl; from adhesive-installed flooring; and from allowing foot traffic too soon after the installation.

Shrinkage in wood flooring, as in furniture, will be more prevalent during the winter months, when artificial heating systems are being used. The cracking is not unusual; during damp, humid months, the cracks tend to disappear. Square-edge flooring will appear to have more shrinkage cracks than bevel-edged flooring.

Incorporating the same methods to protect wood flooring as are used in protecting wood furniture will alleviate the cracking problem. First and foremost, moisture must be added to the room’s environment. Manufacturers of wood flooring will recommend a relative humidity of 50% to prevent shrinkage. Humidifiers are the best choice to provide the moisture level required. Alternate methods may work as well, depending on the humidity levels normally experienced in the home.

Proper humidity control is not only essential to prevent the shrinkage that comes from the constant expansion and contraction of the wood, but also prevents serious “cupping” problems in homes that are left unoccupied for weeks at a time.

The loss of bond is due to used of an improper moisture barrier


Buckling is often called “tenting.” It occurs when excessive moisture is present, and results in the wood’s expansion. Because the floor is restrained at immovable points, such as walls, or adjoining marble or ceramic tile, the wood has only one direction it can go: Up. This results in the center of the floor releasing and lifting upwards, creating a buckling, or tenting, effect.

The problem, though caused by moisture, may be prevented, unless contributory causes are also present. Insufficient mastic; incorrect trowel size; poor adhesive transfer; and substrate contamination can all contribute to the buckling of the floor. When buckling occurs, replacement is probably the only course of action. Of course, the moisture source that caused the original problem must be eliminated to prevent a reoccurrence.

Cracking, or shrinkage, is due to loss of moisture in the wood

Peeling, Bubbles, and Staining

Staining, or discoloration, is a result of moisture, and will be discussed more in-depth in a future article. If the finish is peeling, one cause may be the stain, which has the capacity to leave heavy pigments on the surface. Another possibility is that the first coats of stain were simply not allowed enough time to dry thoroughly.

There is also the possibility of surface contamination. In one instance, the contamination was the result of grains of sand that went undetected. Where did the sand come from? From a residue of sand used as a leveler beneath the wood flooring.

Corrections for these problems range from sanding and refinishing to screening and recoating. Careful consideration of the surface before engaging in the staining and finishing process will go a long way toward having an installation the homeowner, and the installer, will be proud of.

Obviously, some of these problems will never occur if the proper attention is given to the manufacturer’s installation instructions. And as a final step, it is especially important that the homeowner is made aware of the proper methods for maintaining their new wood floor.