LEEMICK underfloor heating Systems are suitable for most floor finishes, including ceramic tiles, timber and carpets.
Ceramic Floor Tiles (including flagstones, slate etc.)
Underfloor heating works very well with all types of ceramic and stone based floor coverings, as these represent minimal resistance to heat transfer. To avoid cracking of the tiles, a flexible adhesive should be used and on large areas, it may be necessary to include a reinforcing mesh in the top quarter of the screed. This will accommodate the expansion and contraction of the floor due to heating.
Plastic or Vinyl Floors
Plastic floorings represent little resistance to heat transfer and are most suited to underfloor heating applications. The floor covering and the adhesive used with the covering should be suitable for temperatures of 400C and show no softening or loss of adhesion at these temperatures.
Timber floor finishes represent a small resistance to heat transfer, which must be taken into account at the design stage. As the timber will be heated, it is essential that a low moisture content timber be used, having moisture content of less than 10%. If a timber with a greater moisture content is used, then there is a risk of shrinkage during the heating season resulting in gaps between the planks. For timber suspended floors, no further action is required With screeded or concrete floors where a timber finish is to be used, it is essential that the screed or concrete is fully cured. This takes approximately 21 days. Following curing and before the timber floor is laid, the heating must be run for a minimum of two weeks. The heating is started at a low temperature and then the temperature is increased by a few degrees per day until its normal operating temperature is reached. The heating should then be turned off and the flooring laid the following day. This avoids moisture being taken up by the screed. It also ensures that all of the moisture in the floor, which would cause the timber floor to warp, is removed.
Carpets will restrict the heat transfer and this must be taken into account at the design stage. It is important to keep the resistance to heat transfer within acceptable limits. Carpet and underlay combinations must not have a thermal resistance of greater than 0.15m K/W (Tog 1.5). If carpets are to be stuck down, the adhesive used must be suitable for temperatures of up to 400C.