Onix Tubing Installation Manual

page 50 Watts Radiant: Onix Installation Manual
After the secondary base course is
installed, a 1/2" to 1" layer of sand
base is placed and leveled. Bricks are
placed on this secondary base course
and often vibrated, so sand fills all the
joints between the bricks. Sometimes
additional sand must be swept into the
brick joints, again depending on the
local engineer and contractor recom-
mendations. The stability of the brick
pavers is very dependent on these
brick joints being properly filled with
sand, and upon the perimeter of the
brick surface being firmly held in
place. If the perimeter of the bricks is
not secured, the bricks will tend to
drift apart.
If sand is not present in the joints
when the bricks are installed over base
material, unwanted movement of the
bricks may be experienced, resulting
in an uneven finished surface.
Refilling the brick joints with sand is a
task that may have to be repeated sev-
eral times, or until all the joints are
completely filled. Contact the local
brick supplier and local contractor for
professional advice in this matter.
General Site Preparation
Snowmelt slabs should be placed on
well compacted material, consisting of
rock or sand. Load issues need to be
discussed with a structural engineer or
the project supervisor.
The snowmelt area needs to be
designed with drainage in mind. Water
will run off of the snowmelt area in
the same manner as rain. External
areas outside the snowmelt zone, such
as water drain ways, outside the
snowmelt zone may be blocked by
snow, ice or slush. Drain locations and
runoff profiles need to be designed
with winter conditions in mind. In
some cases, extra Onix tubing may
need to be installed around drain lines
to prevent water from freezing.
A
radiant slab should never be placed
directly on top of solid bedrock, as this
material can rapidly conduct heat from
the slab into the earth. Crushed rock
and/or insulation must be installed
between the slab and rock.
Sometimes one to two inches of sand
is placed on top of the coarser base
rock material. This gives a smooth,
level surface to lay down rigid insula-
tion (if necessary), and helps prevent
possible breakup of the rigid insulation
in high traffic areas prior to concrete
placement. The sand layer also allows
for more precise leveling to minimize
any variation in the slab thickness.
Insulation Details
Unlike a interior slab applications
where the insulation is recommended,
snowmelt systems do not require insu-
lation. This is due to:
1. Loading.
Snowmelt areas will experience
higher loads than standard interior
heating applications. Heavy vehicu-
lar traffic, such tractor-trailers, may
cause the insulation to compress.
This compression increases the risk
of cracking in a slab.
2. Heat Transfer.
Heat moves to cold. The coldest
point of a snowmelt system is the
surface. Heat will naturally move
more towards the surface than to the
ground below.
Onix installed in a slab on grade snowmelt application.
Snowmelt
Rewire/
Rebar
Onix
Slab
Supply/Return Manifold
Base Material