Under floor heating in wet room - TilersForums.co.uk | Tile Forums

**Sir Ramic** · 23-01-2008

Just been asked to lay UFH in a wet room but i am concerned due to the fact that the waterproof membrane supplied is to be stuck to the 18mm chipboard floor by peeling the back of the membrane.
I have just read something online from the makers of another UFH system similar to the one i am using (Devi Mat) that a 3 - 6mm gap must be laid between the membrane and the UFH.
It still sounds a bad idea to me but what do you think?
Going to have ameeting with the client on Friday to discuss other stuff so i need to be armed with info.
With the membrane (2mm) the spacing using levelling compound (3-6mm) the mat (3.3mm) the adhesive ( 5mm) and the tile ( approx 10mm) he will have one hell of a step up into the room...about 23 - 25mm.

**grumpygrouter** · 23-01-2008

Quote:

Originally Posted by Sir Ramic

Just been asked to lay UFH in a wet room but i am concerned due to the fact that the waterproof membrane supplied is to be stuck to the 18mm chipboard floor by peeling the back of the membrane.
I have just read something online from the makers of another UFH system similar to the one i am using (Devi Mat) that a 3 - 6mm gap must be laid between the membrane and the UFH.
It still sounds a bad idea to me but what do you think?
Going to have ameeting with the client on Friday to discuss other stuff so i need to be armed with info.
With the membrane (2mm) the spacing using levelling compound (3-6mm) the mat (3.3mm) the adhesive ( 5mm) and the tile ( approx 10mm) he will have one hell of a step up into the room...about 23 - 25mm.

Personally I would follow Devi Mat's instructions, not the competitors instructions. If anything fails then it will be back to Devi Mat for assistance.

Grumpy

**wivers** · 23-01-2008

I layed a wet room floor just before xmas with the same thing mate.
The membrane was stuck to wood and it proper sricks mate. Then there's another sheet on top of the membrane you peel back before laying the UFH and this leaves the floor just as sticky. When i say its sticky i mean when i lifted the hand i was balancing on off the floor, it left a layer of my skin, no joking!

I used a matting UFH then pit a layer of reapid set flexi just to cover the wires over. I was gonna use self levler but the customer was worried about losing the slope into the drain. Its all been fine and i was using ceramic sheet mosiac.

**wivers** · 23-01-2008

[Attachment 914
Attachment 915

**Sir Ramic** · 23-01-2008

Reading the info it says to put 3-6mm layer of leveller over the membrane before the UFH. Need to get this sorted before friday.
Nice floor by the way.

**IvegotsTILE** · 23-01-2008

My necks hurting from the first picture Wiv's,lazy git couldn't you have turned it around.

**wivers** · 23-01-2008

LOL
.
ive missed you Ive my little late 80's friend