Solving Flooring Failures

3 03 2010

I recently returned to one of my favorite resort areas (Black Butte Ranch) to update some finishes in a cabin.  One of the items was replacement of an old vinyl floor which had failed (not my installation).

Floor coverings fail due to a number of factors; defective product, poor installation, incompatible substrate, temperature & moisture fluctuations, structural stresses, etc..  Usually, it’s a combination of these that seal the demise of a floor covering.

This vinyl was cracked, pealing up, the seams were too many, and had separated.  It came-up way too easily upon demolition, as if something had caused the adhesive to fail.  Underneath it, the installer had replaced the particle-board underlayment with a very well installed plywood underlayment (nice job).  It’s difficult to be sure just what caused it to fail.  The failure was worse near the entry, leading me to believe that moisture and/or temperature may have contributed to the failure (snow drifts against the door and sits for long freeze/thaw cycles, causing moisture & cold to wick under the door’s threshold).  The bond was better in the center (traffic path) and under the refrigerator.  Expansion and contraction, along with moisture (wet mopping) may have caused the seams to fail (moisture enters the assembly via unfinished & uncaulked base boards and cracked seams).  I measured the moisture content of the plywood at a consistent six (6) percent, which is dry enough by industry standards.

Preventative Measures:
I caulked under the threshold of the entry door with Vulkem, a polyurethane product.  I then installed sill-seal foam as a perimeter expansion joint, and Ditra tile-backer to help isolate the installation from structural stresses.  The Ditra along with Kerdi-Band seams will prevent moisture from entering the plywood from above.  I adjusted the tile layout to locate expansion  joints on logical room separations, further isolating the system from structural stresses.  The expansion joints were constructed of foam backer-rod topped with color-matched, sanded caulk.

The lesson:

Resort properties, unoccupied for long winter periods, in climates which see extreme temperature and moisture fluctuations, provide a recipe for failed installations.  It pays to do your homework, select products and methods which help to withstand harsh conditions, and keep the thermostat on low, even when unoccupied.

John Weber,