Onix Tubing Installation Manual

page 10 Watts Radiant: Onix Installation Manual
6. Use Strips, not Planks.
The narrower the board, the less
movement it will create. The ideal
size is 3" to 3-1/2" in width.
7. Quarter Sawn vs. Plane Sawn.
Quarter sawn wood will expand in
height while plane sawn wood will
expand in width. A quarter sawn
board is more dimensionally stable
than a plane sawn board.
Controlling Moisture
Hardwood floors are installed over a
concrete slab or a wooden subfloor.
The most common cause of moisture
problems in a new home is moisture
trapped within the structure during
construction. Problems sometimes
arise from a continuing source of
excess moisture - for example, from
the basement, crawl space or slab.
For a slab on or below grade, a mini-
mum 6 mil plastic vapor barrier should
be used under the slab to prevent the
absorption of ground moisture through
the concrete during the non-heating
season. Verify with local code and
building practices.
Before wood flooring is installed over
any slab or elevated thin slab, the slab
should be well aged. Preferably, the
slab should have been heated for at
least a week before the flooring is
delivered. Pre-heating the slab before
flooring installation will drive out
residual moisture that might cause
problems. This pre-heating must be
done before a surface vapor barrier is
installed.
There is a simple procedure for check-
ing the presence of excessive moisture
in the slab. Tape a 4 ft. x 4 ft. section
of polyethylene plastic sheeting to the
surface of the slab and turn on the
heat. If moisture appears under the
plastic, the slab should be heated for
another day or so and then checked
again for moisture. If a hardwood floor
is to be laid over a wooden subfloor,
similar precautions should be
observed, as the plywood subfloor
may also be saturated with moisture.
The recommended procedure is to first
drive off the moisture in the slab, then
heat the plywood subfloor for a few
days before unwrapping the finish
flooring from its factory packaging.
Plywood or oriented strand board
make good candidates for subfloor
materials in radiant installations.
Do
not use particleboard as a subfloor.
USDA Forest Service
The following procedures are recom-
mended by the USDA Forest Services
Wood Handbook .
Cracks develop in flooring if (the
wood) absorbs moisture either before
or after it is laid, and then shrinks
when the building is heated. Such
cracks can be greatly reduced by
observing the following practices:
1. Specify flooring manufactured
according to association rules
and sold by dealers that protect
it properly during storage and
delivery.
2. Do not allow the flooring to be
delivered before the masonry and
plastering are completed and fully
dry, unless a dry storage space is
available.
3. Have the heating plant installed
before the flooring is delivered.
4. Break open the flooring bundles
and expose all sides of the flooring
to the atmosphere inside the struc-
ture.
5. Close up the house at night and
raise the temperature about 15¡F
above the outdoor temperature for
3 days before laying the floor.
6. If the house is not occupied imme-
diately after the floor is laid, keep
the house closed at night or during
damp weather and supply some
heat, if necessary, to keep the
house at about 65¡F.
Standard slab on grade
construction
Without a vapor barrier: moisture
moves through a slab via capillary
movement.
With a vapor barrier, moisture
is prevented from entering the
slab.
% Moisture Approx. Width
Change Change/Inch
1 1/128"
4 1/32"
8 1/16"
12 5/64"
16 7/64"
20 9/64"
24 11/64"
Potential Shrinkage
Installed Dimension
Potential Expansion
Hardwood expansion.
Floor Coverings