How to Spot Problems with Your Wood Floors
In a comfortable home with slight humidity
variations through the seasons, wood flooring responds by expanding and
contracting. These changes may be noticeable. During warm, humid weather,
wood expands. During dry weather, wood contracts. This seasonal movement is
a normal characteristic of wood flooring, and it never stops, regardless of
the age of the wood. One of the best ways to ensure that wood flooring will
give the performance homeowners expect is to install humidity controls and
ensure that they are functioning before the flooring is installed.
Working with humidity controls
A homeowner who chooses hardwood flooring is making an investment in a floor
that will last 40 years or more, and he or she should protect that
investment by installing humidity controls--a tool that helps the floor
maintain a beautiful, trouble-free appearance.
Cracks and separations between boards
Nearly every floor endures some separation between boards. In winter, when
homes are heated and the air is dry, wood flooring gives up some of its
moisture and therefore shrinks. When that happens, thin cracks appear
between. This is normal, and homeowners should be forewarned of this. It is
acceptable, and customers should not be calling the installers at the first
sign of cracks. Once the indoor heat goes off in the spring, and the indoor
environment regains moisture, most of these cracks will close up.
Cracks in winter--in the drier months--may
easily develop to the thickness of a dime (1/32 inch) for solid 2 1/4-inch
wide strip oak floors. Floors with light stained woods and naturally light
woods like maple tend to show cracks more than darker, wood-tone finished
The cure for cracks? Homeowners should add
moisture to the air during dry periods. It's their choice-live with the
cracks and wait until spring, or else add humidity by opening the dishwasher
after a rinse cycle, switching off the bathroom fan or hanging laundry to
dry in the basement near the furnace. Better yet, install a humidifier in
the furnace, or an exterior air vent for the furnace burner.
If cracks are a concern, laminated flooring
moves less and shows fewer gaps.
crowning" are common complaints that develop with high humidity.
Both problems occur across the width of the flooring material.
Cupping is when the edges of a board are high
and its center is lower. It can occur after water spills onto the floor and
is absorbed by the wood, but high humidity is more often the cause. If the
wood expands significantly, compression set can result as the boards are
crushed together, deforming the boards at the edges.
Cupping is caused by a moisture imbalance
through the thickness of the wood: The wood is wetter on the bottom of the
board than on the top. The moisture imbalance can be proven by taking
moisture meter readings at different pin depths.
The first step in repairing a cupped floor is
to identify and eliminate the moisture source. In the kitchen, it may be a
leak from the dishwasher or icemaker. From outdoors, it might be the terrain
of the lot, with rain and runoff not moving away from the house and
foundation. Indoors, the humidity may need to be controlled, or a plumbing
leak may be causing excess moisture in the basement, which migrates up into
the subfloor and from there into the wood flooring.
Once the source of the moisture is
controlled, cupping can usually be cured. The floor may improve on its own
as it dries out over time. Other times, fans may be needed to speed the
drying process. Once the moisture content has stabilized, the floor can be
reassessed. Choices may be to do nothing at all, to recoat the floor or to
sand and refinish the floor. However, it should not be sanded until
moisture-meter readings indicate the floor is thoroughly dried.
Crowning is the opposite of cupping:
The center of a board is higher than the edges. Moisture imbalance is
sometimes the cause of crowning if excessive moisture is introduced on the
top of the floor, perhaps from water used in maintenance or plumbing leaks
from an overhead sprinkler system. However, a common cause is that the floor
was previously cupped, but was sanded at the wrong time-before the moisture
content returned to normal and the board flattened on its own.
It should be noted that some slight cupping
and crowning may occur naturally, and should be tolerated: The bark side of
lumber shrinks and swells more than the side closest to the center of the
tree. Largely seasonal in occurrence, it's common in wider planks. Its
appearance can be minimized by using a beveled-edge flooring product with a
satin finish, rather than square-edge flooring with a high gloss finish.
The "buckling" of hardwood floors-when the flooring literary pulls
away from the subfloor, lifting up to several inches in one or more
places-is one of the most extreme reactions to moisture that can occur.
Fortunately, it is not a common occurrence.
Buckling happens most often after a floor is
flooded for a time, but there are numerous other causes. On nailed floors,
insufficient nailing, incorrect nails or incorrect subfloor construction are
possibilities. On glue-down floors, the causes range from the use of
incorrect or insufficient mastics to an inadequate mastic transfer, a
subfloor separation or a subfloor contamination. See
Moisture Detection Equipment.
In flooded hardwood strip flooring, the
swelling stress is theoretically high enough to push out walls. However,
before that can happen the nails or the glue holding the flooring to the
subfloor wil1 usually give way, so that the floor bulges upward.
If buckling floors are caught early, spot
repair and replacement may be possible. Once the standing water is removed,
several boards may be taken up from the floor so that air can be circulated
across and below the floor more effectively. Once the floor has dried to a
more stable moisture level, repairs can usually be made.
Some tips on
The enjoyment of wood flooring depends on some routine but minimal
maintenance details. These include:
- Sweep your floors or use a dust mop daily,
but do not use a household dust treatment, as this may cause your floors
to become slick or dull the finish.
- Vacuum your floor regularly, as often as
you would vacuum carpets.
- Clean your floor's coated surface with a
lightly dampened cloth using a recommended cleaning product, and
according to the manufacturer's directions for use.
- Never damp mop a wood floor. In all cases,
use minimum water, because water causes deterioration of the wood
itself, as well as the finish.
- Buy a "floor care kit" that your
installer or flooring retailer recommends instead of counting on a
home-made remedy of vinegar and water to clean your floors. Different
finishes have different maintenance requirements, and it's best to
follow professional advice in this area.
- Clean light stains by rubbing with a damp
- Avoid using mops or cloths that leave
excessive water on the floor. Never let a spill of water dry on the
- Control humidity levels by use of a
dehumidifier or humidifier. You may need to add portable units in some
- Have your floors recoated periodically as
the finish shows wear.
- Do not clean your wood floors with water
or water-based products on a regular schedule. Clean only when necessary
and clean only the soiled areas.