User Guide

82 l uponorengineering.com
Below-grade and
in-slab installation
Alternative methods to
overhead piping include
below-grade and in-slab
piping. In these installations,
the pipe is laid in a trench or
secured to steel-reinforcing
bar (rebar) or wire mesh
and routed to the desired
locations. The piping system
is pressurized (usually 20 psi
above working pressure) and
buried. Because PEX piping is
available in long, continuous
lengths, it is an ideal material
for running below grade or
in-slab without ttings. (See
page 84 for proper trench
preparation.) Always follow
local code when burying
Uponor PEX pipe as some
jurisdictions require additional
sleeving and protection.
Fittings for below-grade
and in-slab
Uponor EP and LF brass
ttings are all approved for
use in below-grade and
in-slab applications. Uponor
recommends EP ttings for
in-slab applications where
required.
Uponor's LF brass is approved
for direct burial in soil per
NSF/ANSI Standard 14
testing which established
minimum performance criteria
for dezincication resistance
(DZR) and stress-corrosion
cracking (SCC) resistance
for PEX ttings intended for
potable water.
Termiticides and pesticides
Uponor AquaPEX piping for
hot- and cold-water distribution
is approved for installation
directly in soil (below-grade) or
in concrete (in-slab) where soil
termiticide/pesticide treatment
is required. This is especially
useful in slab-on-grade
construction. See page 88 for
information about termiticides.
Pre-insulated Uponor
AquaPEX piping
Pre-insulated Uponor
AquaPEX piping is approved
for use in below-grade and
in-slab applications. For
below-grade applications,
Uponor recommends the use
of pre-insulated AquaPEX with
a minimum 1"-thick insulation
due to static soil loads.
Protect piping where it enters
and exits a concrete slab
with 0.025" (0.064mm) thick
protective material, such as
HDPE wrapping, closed-cell
pipe insulation, PVC elbows
and sleeves or equivalent,
that allow expansion and
contraction of the piping.
Ensure proper placement
where piping exits the slab.
These products are described
as slab-penetration protection
devices.
Pre-sleeved Uponor
AquaPEX piping
When using pre-sleeved
Uponor AquaPEX piping or a
protection sleeve, an annular
gap between these protection
devices and the PEX piping
will exist. In such installations,
ll the annular gap between
the protection device and the
PEX piping at the exposed
ends to help prevent pathways
for pests and the mistaken
application of harmful
chemicals into the space
between the PEX piping and
the protection device. Use only
sealants that are compatible
with PEX piping.
Note: The following products
are appropriate for use when
sealing PEX piping and slab-
penetration protection devices:
• Latex caulk
• Latex foam
• Silicone sealant
• Polyurethane expanding
foam
Note: Misapplication of
these products could result
in pooling or puddling of the
products around the PEX
piping, which is prohibited.
Caution:
• If applying termiticides/
pesticides while the installed
PEX piping still has exposed
open ends that are not yet
connected to plumbing
xtures, cap, plug or close
the ends of the piping to
prevent these chemicals from
entering the piping.
• Do not allow organic
(petroleum-based)
chemicals, petroleum
distillates, termiticides or
pesticides to come into direct
contact with PEX piping.
• Fill the annular gap
between PEX piping and
slab-penetration protection
devices (sleeving or PVC
bend guides) at the ends of
the piping to help prevent
pathways for pests and
the mistaken application of
harmful chemicals into the
space between the PEX
piping and the protection
device. Use only sealants
that are compatible with PEX
piping.
• When PEX piping is
continuously sleeved below
or above a slab (such as
when using Pre-sleeved
Uponor AquaPEX piping),
never ll the space between
the PEX piping and the
sleeving with any liquid
chemical, including pesticides
or termiticides. Prevent
pooling or puddling of these
liquids around PEX piping.
• When it is necessary to re-
treat soil near PEX piping,
prevent the puddling or
pooling of the termiticide/
pesticide.
Water service
requirements
Uponor AquaPEX piping and
associated ttings meet the
requirements of American
Water Works Association
(AWWA) C904, Cross-linked
Polyethylene (PEX) Pressure
Pipe, ½" (12mm) through 3"
(76mm) for Water Service.
Use only SDR9 compression
ttings listed in compliance
with AWWA C800 as
referenced in AWWA C904
in water service applications
when transferring from PEX
to a corporation or curb
stop. Be sure to use insert
stiffeners when assembling
a compression tting with
PEX. Commonly available
SDR9 compression tting
manufacturers include:
• Ford Meter Box Company,
Inc.
®
• Mueller Company
®
• A.Y. McDonald Mfg. Co.
®
• Philmac
®
For ⅝" to 1" water meter
connections, Uponor offers
direct ProPEX to NPSM swivel
adapters in straight, elbow and
valved congurations. Refer to
the Uponor product catalog for
more information.
Trace wire
Uponor recommends the use
of trace wire to facilitate the
detection of underground pipe
systems. Trace wire should
be 14-gauge minimum solid
copper with thermoplastic
insulation suitable for direct
burial. Refer to local code for
further requirements.