Install Instructions

IM-PR 566442 1114 (Design Manual)
16
Subfloor
Hardwood flooring can be installed directly over
slab, thin-slab or wood subfloor applications; a wood
subfloor is typically recommended by the National
Wood Flooring Association. For applications over
a slab, a floating floor assembly is recommended.
For applications over a thin-slab, sleepers may
be employed to assist with attachment. When
selecting fasteners, ensure that the length will not
penetrate tubing. If using adhesives that contact
PEX tubing, contact Viega first to ensure that the
adhesive will not damage the tubing. Examples of
installations over slab and thin-slab are shown in
the adjacent figures.
For more information on installation of hardwood
surfaces over radiant flooring, consult the
hardwood manufacturer.
Figure 1-14 Hardwood floor over thin-slab and wood subfloor with sleepers
Floor Joist
1½" Concrete Slab: Minimum ¾"
height of concrete over ViegaPEX
Tubing
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)
ViegaPEX Tubing:
Keep 4" from wall.
Sealant for Gypsum or Poly-
ethylene Film: 6 mil (min.) for
concrete
R-19 Insulation:
Refer to local code for insulation
requirements.
Hardwood Flooring
¾" Plywood Subfloor: The thickness of the
plywood subfloor should always be installed
in accordance with the local building code.
Sleeper
1.4.3 Carpet
If selecting a carpet and underlayment, select
materials that have a low R-value, to maximize
heat transfer and comfort under foot. R-values
for typical carpets and pads are provided in
Appendix G.
The combined R-value of the underlayment and
carpet should be determined prior to selection;
however, the following provides general guidance
for selecting low R-values.
Underlayment
• Typical: Prime and bonded urethane pads,
which are the most typical carpet pads
available, have R-values that can be 4x those
of the best pads. Avoid these if possible.
• Better: Waffled rubber, frothed polyurethane,
hair and jute, at roughly half the R-value of
urethane pads.
•
Best: Thin-slab rubber and synthetic fiber
pads have the least resistance to heat transfer,
at roughly ¼ the R-value of urethane pads .
Carpet
• Thinner, denser, low-profile, commercial-
type carpets (e.g., Berber) are ideal for the
promotion of heat transfer.
• Synthetic material is generally preferable
to wool. Wool tends to have hollow, highly
insulating fibers that resist the flow of heat.