PEX Installation Manual

25
IM-PF 724596 0416
Sleeve to undisturbed
earth with rigid pipe.
11.2 Foundation penetration
Where service lines penetrate foundation or basement
walls, to prevent shearing or pinching off of the tube
when backll below the tubing settles, plastic tubing
must be properly sleeved.
If there is an area of over-excavation through which the
tubing must pass, it shall be sleeved with a larger rigid
pipe (Schedule 40 PVC or equivalent) to undisturbed
earth. The foundation end of the rigid pipe must also be
supported by the foundation wall.
Slight over-excavations (12" or less) do not require
rigid sleeving when the area below the tubing is back-
lled and well compacted to the level of penetration.
Always sleeve plastic tubing where it passes through
concrete. Do not use oil-based caulks or sealants in
contact with tubing.
11.3 Direct burial of Viega PEX fittings
Installing PEX ttings in direct contact with ground
soil (direct burial) may require protective measures.
Refer to the below direct burial requirements for
each tting type.
Viega PEX Press ttings (Zero Lead bronze and
polymer) do not require any protective wrap for
direct burial installations.
Viega PEX Crimp ttings (Eco Brass and Polymer)
and their crimp rings shall be securely wrapped
with tape meeting the following criteria for direct
burial installations.
• Self-fusing
• Formaldehyde-free
• Fully cured silicone tape
• Minimum of 0.020" thickness
The wrap is available from Viega (part number
15320).
11.4 Concrete
ViegaPEX Ultra and FostaPEX tubing may berun 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. Every
effort should be made to use only continuous lengths
of tubing within a slab. If the use of ttings buried in
concrete is 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.
11.5 Installing under the slab
When installing ViegaPEX Ultra or FostaPEX tubing
in the ground under the slab, the tubing should be
snaked from side to side in the prepared trench. 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. Use only continuous lengths of tubing in or
under slab. Any connections shall 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