Hep20 Technical Handbook

Hep 2
O ® Design Considerations
Construction Types & Water Distribution
Hep 2 O ® Within Floor
Screeds
The Hep 2 O ® pipe should be fed
into the conduit at the same time as
the Conduit System is installed i.e.
before screeding. The conduit
system should not be installed on
sub-floors a long time in advance of
screeding as damage by site traffic
could occur.
The junction box is designed to gain
access to pipe fittings, and to allow
pipe cross-overs (which are
normally undesirable within the
floor screed material). For junction
box dimensions refer to Product
Range pages 36 and 37.
The junction box should be drilled
using a hole cutter or spade bit, to
allow the conduit to fit snugly and
click into position to protrude not
less than 5mm inside the box. The
correct drill size is shown in Table 16.
It is important that central heating
pipework should not be run within
the same junction box as cold water
pipework unless there is sufficient
space to fix adequate thermal
insulation, in order to prevent the
warming of cold water. The
prevention of cold water becoming
warm is a Water Regulations
requirement. See Figure 24.
No thermal insulation would be
necessary where the junction box is
used solely for central heating pipes.
If required, the junction box can be
cut in half and installed up against a
wall as shown in Figure 25.
The junction box should be fixed to
the sub-floor (to prevent movement
or ‘floating’ during screeding), and
the fixings provided with suitable
washers. The junction box should
be fixed so that the lid (when fitted)
is level with the adjacent floor finish.
For uneven sub-floors or where the
screed depth exceeds the junction
box height, the box should be
provided with suitable packing
support under the base.
Table 16 Drill size for conduit box holes
Hep 2 O ® diameter Conduit code Drill bit diameter
(mm)
(mm)
Finished floor
level
Conduit Pipe
10 and 15 HXC25/15 and HXC50/15 26
22 HXC25/22 and HXC50/22 32
Junction Box lid,
drilled and secured
by fixing screws
Junction Box secured
to the sub-floor
15 15
15 15
Figure 24
Typical section through Hep 2 O ® Junction Box enclosing hot and cold water
distribution pipes with tees
Figure 25
Hep 2 O ® Junction Box cut in half
Small insulating pad,
cut and placed to
separate pipes at
cross-over
Tee on cold
water pipe
Junction Box lid, drilled and secured by fixing screws
Conduit Pipe
Finished floor level
Junction Box cut in half and secured to floor
Thermal insulation barrier
formed across Junction Box
(if necessary)
Tee on hot
water pipe
Hep 2 O ® pipe to radiator
or sanitary appliance
170mm
Hep 2 O ® elbow
160mm
74