A quick description on installation of backer boards ( insulated)....dave....
Installation onto concrete floor
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 screeds bases should be adequately cured and dried to allow shrinkage to occur prior to fixing the Insulation Board.
The Insulation Board should be bedded onto the prepared base using a flexible cement-based adhesive. The adhesive mortar should be trowelled out and combed through with a suitable notched trowel to give a ribbed bed, any slight depressions being filled by the mortar.
The Insulation Board 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. Immediately after the tape has been fixed, the tiles can be fixed with flexible adhesive.
TILE FIXING
Tiles should be minimum 150 x 150mm and fixed using a thin solid bed fixing technique to ensure no voids are left behind the tiles. Once the tile bed has hardened sufficiently, the joints between the tiles can be grouted using the appropriate grout mortar incorporating an admix or the appropriate flexible cement-based grout.
installing UFH...
Concrete must be clean and dry
- Use cement-based flexible adhesive to attach boards to subfloor
- Stagger board joints
- Cover joints with self-adhesive glass fibre tape
- Allow adhesive attaching board to subfloor to dry
- Lay heater directly onto board ( do not prime board unless tape will not adhere due to dust)
- Tile over heater using cement-based flexible adhesive and grout
Installing on timber floors.....
Ensure that adequate underfloor 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 painted with primer, applied as a thin even coat using a short pile paint roller, and allowed to dry to a clear, tacky film.
The Insulation Board should be bedded onto the dry primed floor using a flexible, cement-based adhesive. The 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 Insulation Board should be laid on the freshly applied ribbed bed and thoroughly bedded in to ensure that, as far as is possible, 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 Warmup Insulation 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.
TILE FIXING
Tiles should be minimum 150 x 150mm fixed in a flexible adhesive using a thin solid bed fixing technique to ensure no voids are left behind the tiles. Once the tile bed has hardened sufficiently, the joints between the tiles can be grouted using the appropriate flexible grout mortar.
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Installing backerboards for UFH... 
Laminate or Wood floors etc:-
A layer of Depron (2 for greater efficientcy) is laid under the heating film this replaces the std (Bubble) insulation normally supplies with Laminates.
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