Instructions / Assembly

Taking a Surface Reading:
hDrive two hardened-steel masonry nails about 3/4”
apart into the finish coat of concrete floor. Drive them
about 1/8” deep so they make firm contact with the
concrete and do not move when touched.
hTouch the nails with the contact pins
^ .
hPress read button
! and read the reference scale. If
the meter reads in the red or “wet” area, it shows the
floor is not satisfactory for covering. If meter reads in
the green or “dry” area, the surface is dry. However,
subsurface tests should be made to verify if the slab is
dry throughout.
Subsurface Test:
hDrill two 1/4” holes, 3/4” apart and 1/2” to 2” deep.
hDrive the masonry nails into the bottom of the holes and
make the tests as described above. Nails must not touch
sides of drilled holes.
If the meter still indicates green or “dry,” the floor is ready
for covering. Tests should be made at several points,
especially when the slab is thick and air circulation is poor.
Tests should only be made in newly drilled holes, since the
inside surface of the holes can dry out while the rest of the
slab is still wet.
Even readings in the red or “wet” area can indicate
relatively low moisture content in concrete. For example,
readings in the 85-95 range on the reference scale indicate
approximately 2% to 4% moisture content.
If more testing is required, the calcium chloride test is
recommended, which measures the moisture vapor emission
rate of concrete. The National Wood Flooring Association
offers the following guidelines when evaluating the results
of the calcium chloride test***.
10
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6”
nails 1/8” into
concrete
Drilled holes 1/4” diameter.
Nails 1/8” into concrete at
bottom of holes.
2-3” approx.
slab
electrode
subsurface
Results Indicate
0-3 lbs. Dry
over 3 lbs. Moisture barrier required
over 7 lbs. Too wet