Onix Tubing Installation Manual

Snowmelt
Applications
Introduction
Radiant snowmelt and ice removal
systems for concrete and sand and
brick pavers are installed in the same
manner as shown for a standard con-
crete slab. The main differences tend
to be the tubing size. Due to the
increased pumping requirements for
the higher loads, a larger diameter
tubing is needed to keep an acceptably
low pressure drop.
Although there are several similarities
between a slab snowmelt project and a
brick paver project, there are some
important distinctions.
Brick Paver
Onix can be installed under brick
pavers for the purpose of snow melt-
ing. While Watts Radiant does not
hold itself as expert in the art of brick
paving, there are several precautions to
observe.
The thickness of the paving bricks
must be selected according to the man-
ufacturer s printed cautions and load
limitations. Bricks not thick enough to
support the design load will crack
and/or shift in service.
There are three installation methods
described below. Once a determination
is made as to which method is pre-
ferred, RadiantWorks should be used
to take into account the insulation
value of the concrete (or alternate base
material), sand, and bricks over the
heating circuits. Base, sand, and brick
materials retard the passage of heat,
and must be compensated in the
design of the snowmelting system..
There are three general types of instal-
lations for Onix installed under brick
pavers:
1. Concrete.
The easiest and most predictable
substrate is concrete, where Onix is
typically embedded in the slab, and
the bricks are adhered to the top of
the slab. Consult with experts in the
field to ensure that the correct adhe-
sives are used to secure the bricks to
the concrete, and the slab will meet
the load requirements of the expect-
ed traffic.
2. In the First Course
of Base Material.
The Onix may be imbedded in the
first course of base material. A local
engineer should determine the type
of base material chosen, the thick-
ness of the base, and the degree of
compaction. The depth at which the
Onix is buried should be determined
in consultation with the local engi-
neering firm. The first course of
base material is typically compacted
base rock, mixed with fines to pres-
ent a relatively impervious surface.
3. In the Second Course
of Base Material.
To improve system response, the
Onix may be placed on top of the
first course of base material. The
Onix is then covered with approxi-
mately two or more inches of
smaller base material. The depth at
which the Onix is buried should be
determined in consultation with the
local engineering firm.
Snowmelt
Onix installed in a sand and brick paver application.
Watts Radiant: Onix Installation Manual page 49
Rewire/
Rebar
Onix
Brick Paver
Supply/Return Manifold
Base Material
Sand/Crushed Stone Layer