Log in to view the full article
The Problem
I was hired by a consumer to inspect her buckling 2¼-by3 / 8 -by-random length factory finished engineered oak floor.
The Procedure
The customer purchased her flooring from a big box store and hired an independent installer to remove the existing floor coverings and install 190 square feet of new wood. A few months after installation, it began to buckle. The installer inspected the floor, made a relief cut and removed three rows of boards from the center of the floor.
The house was a small bungalow at the Jersey Shore built in the early '50s. The homeowner explained she turns the heat or AC off when she's at work or on vacation. It was after a weeklong summer vacation that she returned to find the flooring buckled.
The Cause
The inspection was simplified by the installer, who had removed three rows of boards through the center of the living room and kitchen.
The exposed areas revealed an existing felt-backed sheet vinyl in the kitchen and outlines of 9-by-9-inch vinyl asbestos tile (VAT) that had been removed by the installer (VAT is common in these homes).
The relative humidity measured 62 percent at 78 degrees Fahrenheit. The wood's moisture content was measured with an invasive probe meter measuring 10-11 percent on the surface of the boards, and 12-14 percent on the bottom. Concrete moisture readings were 4-5 with a non-invasive concrete meter.
In the kitchen area, I found the wood flooring glued directly to the paper backing from the old vinyl floor. The vinyl had been installed directly to the concrete over cutback adhesive. On the back of the boards I found the vinyl's paper backing with cutback adhesive on the underside of the paper. Mold growth was present on the paper backing, on the floor and on the bottom of the boards. I removed a few more boards from the living room to find cutback adhesive and an inconsistent spread of wood adhesive on the back of the boards. There were no moldings installed—the wood flooring was installed net to the walls and cabinets.
The lack of indoor climate control and high concrete moisture resulted in elevated moisture in the wood, which caused expansion of the wood flooring, which had no expansion space. Because the wood was laid into a bed of cutback adhesive and vinyl paper backing, it was not adhered to the concrete. A combination of expansion and lack of bond caused the wood to buckle off the floor.
How to Fix the Floor
Unfortunately, this floor could not be salvaged. To prepare the subfloor for a new glue-down installation, the cutback adhesive and paper/felt backing must be removed. The concrete requires moisture testing and possible remediation before installing a new glue-down wood floor. Another option would be to install a floating wood floor over an approved moisture retarder.
In the Future
First, customers should receive maintenance instructions and information regarding proper climate control at the point of sale. Second, the NWFA and most flooring manufacturers recommend a flat, clean, dry and structurally sound subfloor; this subfloor was not clean or dry. Cutback adhesive is not compatible with wood flooring adhesives; it is necessary to remove or encapsulate cutback residue before installing a new floor.
Having lived and worked in this area for over 30 years, I have no doubt the tile removed from this house contained asbestos. For safety's sake, before removing resilient or tile flooring, the floor should always be tested with an asbestos test kit (available at home centers and hardware stores). If asbestos is present, removal instructions are available from The Resilient Floor Covering Institute at www.rfci.com.