The Homeowners' Issue

The homeowner purchased an older home, had it remodeled and wanted a new plank wood floor. The builder hired a wood flooring contractor to install the new floor. Due to height limitations with staircase elevations and exterior doors, an engineered floor was selected. The contractor used self-leveler on the slab and glued the flooring down. One month after moving in, the homeowner noticed the wood floor had hollow sounds when walked on and called the builder. The builder and the flooring contractor examined the floor and said it's normal to have some noise. The homeowner disagreed and contacted a certified wood floor inspector.

Roy: The Inspector's Observations

I could feel the wood floor was not flat and that it moved underfoot when walked on. Using a 6-foot level as a straightedge, I found the floor was not flat by almost 13/32 inch in 6 feet. The flooring adhesive manufacturer requires a flatness of 3/16 inch in a 10-foot radius or 1/8 inch in a 6-foot radius. Destructive testing in the area with a hollow sound revealed the flooring was suspended off the substrate by 4/32 inch, and in some areas there was no adhesive under the plank with deflection. A minimum of 80% coverage and transfer to the back of flooring is required for the single-component adhesive used. Some hollow sounds would be considered normal on an 80% coverage system, but this floor has vertical deflection between the planks in the areas where no adhesive was present. I concluded that this wood floor installation failed on two accounts: substrate flatness and a lack of adhesive under areas of plank deflection.

Blake: The Attorney's Analysis

The wood floor installer is responsible for this failure. The floor was installed incorrectly, failed to conform to the manufacturer's guidelines, and the installer will need to fix it. The real moral of this story, however, is that instead of insisting that nonconforming site conditions be corrected, installers too often take their chances and install the floor anyway. The installer should always review the manufacturer's specifications and verify that the subfloor is within specifications. If there are any apparent issues, then the installer should discuss the conditions with the applicable parties and make sure the problems are corrected before installing the floor. The installer could also contact the manufacturer's technical services department to seek guidance and a written confirmation regarding how to proceed. If the manufacturer sends an email stating that the installer may proceed under the conditions described and a problem with the floor develops later, then the installer could deflect blame onto the manufacturer. If instead the manufacturer says not to proceed, the installer has a great reason to wait until the issues are addressed. It is a hard decision to cause delays to a project, but as the old adage goes, "An ounce of prevention is worth a pound of cure." Or perhaps more appropriate for the wood flooring trade, "Measure twice, cut once."

Blake R. Nelson is a construction-law attorney with Hellmuth & Johnson PLLC in Minneapolis. He can be reached at Roy Reichow is president at National Wood Flooring Consultants Inc. and an NWFACP-certified inspector. Read his WFB Inspector Blog at