tiling to bathroom floor...

[newpark7]

Hi Dave ( dhceramics )

You have kindly helped me out in the past regarding tiling issues - I am going to look at a job tomorrow where the customer wants underfloor heating installed and tiled on top. They have just had central heating installed and the floor is just bare joists so I have a blank canvas as to what timber floor goes down.

What do you recommend as I cannot afford for this to fail as he owns a chain of nursing homes and has promised a good run of work for me.

Any advice would be greatly appreciated.


Mark

[Dave]

If i was you mate then i would sheet on top of the joists with 22mm exterior grade ply...put noggins in between the joists at 300mm centres and then when you lay the ply then you can screw it down every 300mm in either direction....
prime the floor the with bal bond neat..lay your ufh then i would cover this with arditex smoothing compound..this then protects the ufh from getting damaged while tiling and provides a nice flat floor to tile too.....use the usual flexi adhesives and grout....good luck mark........

[newpark7]

Thanks Dave

I have today fitted all the noggins as suggested (used 4" x 2")and was really surprised at how much it stiffened the floor up, I could only get 18mm ext ply or 25mm I opted for the 18mm to match the small area of 18m chipboard that already exists.

Hope fully this should be enough as there is only about an 8 inch strip of chipboard floor remaining along one wall. The smoothing compound you mentioned is this self levelling? and what sort of thickness do I apply it, do I have to float it to a finish etc.

Thanks again


Mark

The term self levelling is a bit misleading as i have never come across one of these smoothing compounds that self levels. Good thing is though,that the heating element that you will be levelling, sorry, smoothing over, will act as your depth gauge. trowel the correctly mixed compound so that you just skim over the element. Areas where the element is not laid ,such as the toilet pan, you will just have to be careful to trowel to the same depth.

[Dave]

spot on len mate arditex is quite thick to use..but pour small amounts and you will be ok...

[GazTech]

[IMG]http://www.inspiredheating.co.uk/acatalog/warmup-insulation-board.jpg[/IMG] [B]Warmup Insulation Board[/B]
Length: 1250mm
Width: 600mm
Thickness: 10mm

WARMUP INSULATION BOARD is a water resistant insulated tile backer board made of extruded polystyrene, faced on both sides with a fibreglass mesh embedded into a thin cement polymer mortar.

WARMUP INSULATION BOARD can be used as a structural tile backer board in the floor. It will withstand a load of 30 tonnes per square metre. It is ideal for use with underfloor heating as it pushes the heat into the room, by not allowing heat to penetrate down into the concrete substrate below. As a wall tile backer board, tiles can be fixed directly on to the surface without prior preparation and, being totally waterproof, is ideal for use in bathrooms or showers.

WARMUP INSULATION BOARD will save you money when used in conjunction with undertile heating by acting as a very efficient thermal barrier. It reflects the heat upwards into the floor tile instead of allowing heat to warm up the concrete slab below. By using WARMUP INSULATION BOARD you will find that after switching on your heating, your floor tiles will warm up in about 10-15 minutes. Without WARMUP INSULATION BOARD it could take anything from 2-3 hours, or more............
I certainly recommend thes for maximum efficiency of ufh....Gaz

I think if possible I would of tried to incorporate a tile backer with the heating, excellent oppotunity missed when it was open joisted.

[newpark7]

Thanks everyone for the helpful info I will give it a go.