A.Tandy Reeves, a certified
flooring inspector and CEO of Flooring Inspection
Training Services in Tulsa, Okla., responds:
Even though engineered hardwood flooring is more
dimensionally stable than solid wood flooring, the
wood-veneer layers that make up the face are
susceptible to shrinking and swelling with changes
in temperature and humidity. It's common for the
top layer to face-check when the humidity varies as
much as you describe, but most of that may
disappear as the relative humidity elevates again
over the summer.
As with all wood floors, one key to a successful
installation — and to the long-term life
of the wood floor — is to install and
maintain the floor at a temperature between
60°F and 80°F, with the relative
humidity measuring from 30 percent to 50
percent.
Another is to install the flooring when it has
reached equilibrium with the room environment,
which is when the moisture content of the subfloor
and that of the new flooring are within 2 percent
to 4 percent of each other. This should be checked
using a good pin-type moisture meter, and the
readings documented in case there are issues with
the installation later on.
If the flooring doesn't return to its originally
installed condition after seasonal humidity levels
return to normal, you can replace the worst planks
(rather than the entire floor). After cutting out
and removing a plank, you may need to use a router
and rasp to clean dried glue off the
tongue-and-groove profile of the remaining sections
of flooring. Then trim off the underside edge
profiles on the ends and one side of the new plank
so it can be slipped into position; apply yellow
carpenter's glue to all of the edges; install the
new plank; and weight the installation for at least
three hours, or until the glue has cured.
Check with your flooring manufacturer for its
step-by-step instructions for plank
replacement.