Durabase and underfloor heating

**mack1** · 03-04-2010

I am planning on installing underloor heating under travertine tiles. I have also bought 12mm Marmox insulation and also plan on laying a durabase membrane. Can anyone advise on the following:

1. Should the durabase be put over or under the heating?

2. The floor needs to be levelled - Would I be best to put this over/under the insulation or pour over the heating cables before the tiles?

Any advice gratefully received. Thanks.

**whitebeam** · 03-04-2010

I take it this is on a screed floor

**mack1** · 03-04-2010

No,its going on top of original t&G flooring.

**whitebeam** · 03-04-2010

I've never used any insulation on floor boards, either used 6mm hardie backer or ply.

**mikethetile** · 03-04-2010

the floor will need overboarding with 18mm ply anyway to take the deflecton out of the floor

**whitebeam** · 03-04-2010

I would lay the ufh on the ply, slc, durabase, then tiles.

**mack1** · 03-04-2010

Thanks.

Have increased strength to floor by doubling up on joists and cross braced as I do not want raise the height of the floor too much - thats the reason I have decided to use durabase.

**Daz** · 03-04-2010

If the floor is solid with no deflection, then I would build the insulation boards out with some extra adhesive so that the floor is fairly level. Fit the decoupling membrane, then UFH, then slc, then tile.