We recommend the use of Marmox tile backer boards when tiling onto walls and floors.
Marmox board is made from extruded polystyrene embedded in a cement polymer mortor, this is highly waterproof and has high thermal insulation making it ideal with underfloor heating ensuring the room heats up quickly, and reducing heat loss by upto 60%. Marmox board can hold a tile weight of 62kg/m2 making it suitable for slab and stone tiling work.
Ensure that adequate under-floor ventilation is provided. Existing floorboards should be securely and rigidly fixed (refer to BS 5268 : Part 2 : 1991 regarding minimum floor stiffness and rigidity).
The surface of the floorboards should be primed with Ardex P82 primer, applied as a thin even coat using a foam or short pile paint roller, and allowed to dry to a clear, tacky film. The Marmox Construction board (minimum thickness 10mm) should be bedded onto the dry primed floor using Ardex S16 cement-based adhesive incorporating E90 admix. The flexible adhesive should be trowelled out and combed through with the recommended notched trowel to give a ribbed bed, any slight depressions being filled by the mortar. The Marmox Construction boards should be laid on the freshly applied ribbed bed and thoroughly bedded in to ensure that, as far as is practicable, no voids are left beneath the boards and they are solidly supported. All boards should be laid with staggered joints. To attain waterproof joints the boards should be sealed during fixing using Silicone Sealant. The sealant should be applied to the edge of the fixed board immediately prior to the next board being installed and placed in position.
When this adhesive has set but not necessarily dried, the boards should be supplementary fixed using a screw fixing and washer. These are fixed at the rate of 5 per square metre. The fixings should be a minimum of 30mm from the edge of the Marmox Construction board. The screw washer fixing is tightened into the board until the screw head is flush with the surface. If required, it may be driven flush with the board surface using a rubber headed mallet and the screw re-tightened. In wet areas, we recommend that the fixing hole be primed with Silicone Sealant prior to inserting the fixing. The joints should then be reinforced with a self-adhesive glass fibre tape approximately 50mm wide.
Tiles should be installed using a thin solid bed fixing technique to ensure no voids are left behind the tiles. A flexible tile adhesive such as Ardex X77, Mapei Keraquick or similar flexible adhesive is recommended. Once the tile bed has hardened sufficiently, the joints between the tiles can be grouted using the appropriate Ardex of Mapei flexible grout.
The Marmox Construction boards must not bridge movement joints in the sub-floor. The integrity of such joints should be maintained through the board/tile bed and should be sealed in the appropriate manner.
Existing concrete bases and screeds should be mechanically prepared removing all traces of existing finishes, contamination, etc., to expose a clean surface.
New concrete or screed bases should be adequately cured and dried to allow shrinkage to occur prior to fixing the Marmox boards. The Marmox Construction boards should be bedded onto the prepared base using Ardex 7001 or X7G Plus cement-based adhesive. The Ardex 7001 or X7G Plus adhesive mortar should be trowelled out and combed through with the recommended notched trowel to give a ribbed bed, any slight depressions being filled by the mortar.
The Marmox boards should be laid on the freshly applied ribbed bed of adhesive and thoroughly bedded in to ensure that, as far as is practicable, no voids are left beneath the boards and they are solidly supported. All boards should be laid with staggered joints. To attain waterproof joints the boards should be sealed during fixing using Silicone Sealant. The sealant should be applied to the edge of the fixed board immediately prior to the next board being installed and placed in position.
The flexible adhesive must be allowed to harden before the joints are reinforced with a self-adhesive glass fibre tape approximately 50mm wide.
Tiles should be installed using a thin solid bed fixing technique to ensure no voids are left behind the tiles. A flexible tile adhesive such as Ardex X77 or Mapei Keraquick is recommended. Once the tile bed has hardened sufficiently, the joints between the tiles can be grouted using the appropriate Ardex of Mapei flexible grout.
