Underfloor Heating

typeractive

Well thank you very much. It beats being a bit cold and dense I guess - a bit similar to the qualities of concrete...

SusanA_2

Hi there, I work at Creative Tiles and Laminates a tile shop in the West Midlands which also has its own fitting team. We have been fitting electric underfloor heating for over seven years and using the Varme system since 2004.

In our experience if you are using a 10mm insulation board, tile backer board or similar eg. Marmox - then as long as this is securely fixed over the floorboards in 150mm centres in a grid format there would be no reason to also use ply. As a double protection, you can also bed in the insulation boards using a 2 part rubber crumb flexible adhesive alongside the mechanical fixing. The only reason to go back to the joists would be if you had a height issue.

Use a mat that is roughly 85% of the floor area to be covered although in a bathroom (depending on the layout) it may be easier to use a cable kit which can be layed in more awkward layouts. You should also use a levelling compound over the electric cables when fitted (as recommended by the Tile Association), and of course use flexible adhesive and grout.

My bathroom has floorboards, 10mm insulation boards, underfloor heating, leveller and polished porcelain tiles fitted with flexible adhesive and grout. It was fitted 4.5 years ago and works perfectly, with no cracks, loose tiles, uneveness or lipping (although I do know a good tiler ). The bathroom connects to the hallway which has laminate flooring with an adaptor bar/ramped door bar which can take out the height difference.

I hope this advice helps.