Install Instructions

Water Service Installation
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IM-PF 724596 1021 PureFlow Water System (EN)
7.4 Concrete
Viega PureFlow PEX tubing can be installed within concrete slabs. All penetration
points must be sleeved to prevent tubing damage (entry/exit points, expansion
joints, etc.). Penetrations in walls, etc., may be sealed with silicone caulk. Do
not use oil-based caulk. Best practice dictates that only continuous lengths of
tubing should be run within the slab. Viega does not recommend the installation
of 󶈵ttings within a slab as part of a design. Fittings should only be used in a slab
if they are necessary to make a repair. If the use of 󶈵ttings buried in concrete
are necessary for repairs, all such 󶈵ttings must be wrapped with insulation,
noncorrosive tape (no adhesives), or sleeved to prevent corrosion. The wrap shall
be a self-fusing, formaldehyde-free, fully cured silicone tape with a minimum of
0.020" thickness. The wrap is available from Viega (part number 15320). Contact
a Viega representative for additional information on approved wrapping materials.
When running tubing within a concrete slab, the tubing must be fastened
to the reinforcing mesh or rebar every two to three feet to prevent it from
󶈶oating up while concrete is curing.
7.5 Installing Under the Slab
When installing Viega PureFlow PEX tubing in the ground under a slab,
the tubing should be snaked from side to side in the prepared trench to
provide for contraction due to temperature change. The trench bottom
should be smooth and free of rocks and debris. Lay the tubing directly on
the trench bottom. Tubing must be continuously supported by the trench
bottom. Best practice dictates that only continuous runs of tubing should
be placed under slabs. Viega does not recommend the installation of
󶈵ttings under a slab as part of a design. Any connections must be outside
the slab or in an access box.
PEX tubing must be sleeved at all expansion joints and every point where
it enters, exits, or penetrates the slab. For expansion joints that are to be
cut, the tubing must be dipped below the slab to prevent damage.
Elbow sleeves protect tubing at concrete slab penetrations.
Tubing must be fastened to the reinforcing mesh on rebar.
Sleeve PEX tubing at all expansion joints
For cut expansion joints, dip the tubing below the
slab to a safe distance at the cut lines