Why use Decoupling Systems when Floor Tiling
Decoupling membranes are designed to neutralize tensions between the substrate and the tiles. The uncoupling membrane helps to prevent stress cracks from transferring through to the finished tiled surface. Some decoupling membranes, like the ones that Target Tiles Stock from Schluter called Ditra Matting. This can be also used with electric underfloor heating systems. The membrane helps to alleviate increased stress that is caused by thermal movement. The uncoupling membrane absorbs the stress and the air spaces under the membrane allow the residual moisture to gradually escape, preventing cracks from forming in the tiles. Decoupling membranes also allow the heat from the underfloor heating system to be spread evenly across the floor surface, increasing the effectiveness of the heating system.
Now we have explained why to use an Decoupling membrane lets talk about the best adhesive to use to fix it. If fitting to wood we recommend Ardex AF200 , using a 2mm x 6mm serrated trowel, apply a ribbed adhesive bed of Ardex AF200 general purpose adhesive over the wood to secure the fabric fleece on the underside of the mat. NOTE: It is important that sufficient adhesive is used to adhere the matting in place. Lay the Ditra Matting into the wet/tacky Ardex AF200 general purpose adhesive and press firmly into place, abutting all edges. If a waterproofing system is required, the mat joints should be sealed with Kerdi Band , secured with the Kerdi Coll adhesive. If fitting to a solid floor we recommend the Ardex Range of powder adhesives.
Target Tiles highly recommend using a decoupling membrane where electric or piped underfloor heating is being installed and tiled upon. Always prime your floor surfaces with P51 before using any adhesive as this is an easy to apply primer and can be brushed on with a broom so helps adhesive adhere to the surface better.