Install Instructions

15
IM-PR 566442 1114 (Design Manual)
Moisture
To avoid cupping or crowning of the hardwood
surface, it should be installed at a moisture
content of 6-8%, over a subfloor within ~4% of
the hardwood moisture content, as confirmed by
a moisture meter. Indoor relative humidity levels
should be between 30-50%. Ensuring these
moisture and relative humidity levels is important
regardless of whether hardwoods are installed
over a radiant panel. To reach the targeted
moisture content, store the hardwood inside,
ideally for several weeks prior to installation.
To dry the subfloor, allow the radiant system
to run for at least a week before installing the
hardwood; longer periods may be required by the
hardwood manufacturer. In areas of large humidity
fluctuations, install humidity control. In vacation
homes with intermittent use, it is recommended to
back-seal the boards prior to installation.
Sources of moisture from below:
• Inadequate moisture barrier
• Ground water wicking through the slab
• Unsealed subfloor
Sources of moisture from above:
• High relative humidity
If the moisture content of the wood is relatively high
near the bottom of the plank, cupping upward will
occur, exaggerating cracks.
Figure 1-11 Cupping
If the moisture content is relatively high near the
top surface of the plank, it will crown downward on
the edges.
Figure 1-12 Crowning
Figure 1-13
Section through slab on or below grade installation with floating floor
4" Concrete Slab:
Minimum ¾" height of
concrete over ViegaPEX
Tubing
R-5 Insulation:
Refer to local code for insulation requirements.
(Ensure compression rating is suitable for
application.)
Fasten tubing every 2 feet and 3
times at each U-turn to hold down
any return bends or other shapes
created.
Tubing Spacing (per design)
Compact Subgrade
Gravel
ViegaPEX Tubing:
Keep 4" from wall.
Polyethylene Film: 6 mil (min.)
R-5 Edge Insulation:
Refer to local code for
insulation requirements.
Wire Mesh
Foam Pad
Floating Flooring