Establishing
the moisture content is a critical component of quality control in hardwood
flooring installation process. Therefore, every floor installer has to be
informed of the amount of moisture content on subfloors and the wood.
Moisture
humidistats and meters are the most important performance tools. If your installer does not have any of these
tools, then they are obviously not aware of the significant
relationship between moisture and wood. Continuing with an installation process
constitutes the acceptance of the work site conditions by the installer or
technician.
A wood-based
subfloor should be within an average 2% moisture content of hardwood flooring.
The average humidity of the house must be between thirty to fifty percent of solid wood
and thirty-five to fifty-five percent for engineered hardwood before, during
and after the installation job. A minimum reading of 10 moisture taken per 500
square feet at intervals of four0inches apart, recording the lowest and highest
measurements.
There
are numerous kinds and brands of moisture reading meters. The Pin-type readers
penetrate into the wood to get the moisture reading. Non-destructive pin-less
meters obtain moisture measurements without penetrating the wood. More often,
the pin-less meter readers give readings, which are not accurate entirely, but provides
a fair reading of moisture content. Meters
that are more expensive on the other hand
have adjustable settings thus more precise.
However, glues in the subfloor affect them.
The
only ideal and accurate method of
measuring the moisture content of wood by weighing the piece of wood then let it dry until there is no moisture
remaining in it. Weigh the dry piece,
less the dry wood weight from the wet
wood weight, and divided by the dry weight.
MC =
[(initial weight- dry weight)/ dry weight] x 100%
Example:
400 grams - 370 grams = 30 grams, divided by 370 grams x 100 = 8.1percentage
moisture content.
Hygrometers
or humidistats are readily available for purchase. Buying and using two units
will maintain accurate results. Take and note these readings throughout the
job.
Before testing a concrete slab, it should be at least
forty-five days old. Use a Calcium Chloride test, which is always accessible at
The Big Box Stores. The moisture level readings obtained using the Calcium Chloride
test must not exceed a maximum of 3lb per 1000 square feet.
The time
duration taken by concrete to cure can cause delays on the job site. A wall or concrete
slab in the best drying conditions with a large dehumidifier in operation will
dry at approximately one-inch per month. Without these circumstances, the concrete wall or slab may only dry at a quarter
inch per month. Concrete heals by hydration when moisture reacts with cement
powder, providing the concrete its strength. However, the mixture always
contains more water than is required for hydration reaction, becoming more
prevalent with the utilization of lightweight aggregate that tends to retain
moisture. In many floor slabs, there could be up to fifty gallons of extra
water for every cubic yard of the pour. Using a dehumidifier with constant airflow
over the plate surface will fasten the
process. When the slab dries, it is
recommended to use a concrete sealer or a
recommended adhesive.
Radiant
heating in such floors, therefore, must
be turned on to a minimum temperature of 22 degrees, seven days prior, to eliminate residual moisture before
installing wood flooring.
