93
Underfloor Heating
Karndean flooring is suitable over
underfloor heating systems, insulated so
that its surface temperature does not rise
above 27°C (80°F).
The system must be switched of 48 hours
before, during, and 48 hours after the
installation, then temperature gradually
increased no more than 2°C per day to
desired warmth. Mesh/wire systems must
be bedded into a base coat of reinforced
fiber smoothing compound to cover the
wires or mesh by consulting your
underlayment supplier. Mega-Bond
adhesive is then used in the normal way.
Subfloor Preparations
Existing Floor Coverings (e.g. linoleum,
PVC, thermoplastic, carpet)
Remove existing floor covering and all
traces of adhesive residues. The subfloor
should be treated as per the subfloor
exposed.
Damp Subfloors
Products must only be laid on sub-floors
where the moisture level complies with
Appendix 'A' testing as per AS 1884. If slab
moisture is above this level, either a Damp
Proof Membrane (DPM) or 'Moisture Fix' by
Protect Crete must be applied.
Painted Floors / Painted Concrete
Mechanically remove all paint back to
original base, prime and apply a
compatible self-leveling smoothing
compound to a minimum of 3mm.
Sealed Concrete/ Mosaic/ Terrazzo/
Ceramics/ Metal Surfaces
Ensure surface is firm, dry and free of wax,
oil, dust and loose tile particles. Apply
Ardex P82 Primer or similar as a bonding
agent and a compatible self-leveling
smoothing compound to a minimum of
3mm ensuring that all grout lines are filled
with no show-through.
Power Floated Concrete
Power floated floors are not suiciently
absorbent for the adhesive to disperse
into the substrate and require the
application of a primer and a compatible
self-leveling smoothing compound.
Cork Tiles
Due to their resilient nature, cork tiles
must be uplifted and adhesive residue
removed using Roberts 550 Acrylic
Adhesive Remover or similar. The exposed
floor should then be treated in the
prescribed manner as per the above
instructions.
Timber Floors
• Standard Floorboards/Tongue and
Groove Floor boards must be firm, level
and completely covered with 5.5mm
thick flooring grade hardboard or
minimum 6.0mm thick plywood - fixed
with staples and neoprene construction
adhesive in strict accordance with AS
1884. For wet areas use fiber cement
sheets instead.
• Fiber Cement Sheeting
Suitable generally and must be used for
wet area subfloors. Being extremely
porous the sheets must first be primed
with Karndean GS400 Primer or similar.
• Particleboard, Chipboard and Pine
Boards. These MUST be covered with
minimum 5.5mm thick hardboard
complying with AS/NZS 1859.4 or
minimum 6.0mm plywood complying
with AS/NZS 2269 in order to eliminate
later potential movement in changing
climatic conditions.