Correct floor for tiling - Tile Advice

[Sohail]

Hello , I wanted some advice for tiling in our new extension floor , I have 8x2 C24 floor joists spaning 3.9 meters long fixed to wall plates via bolts at 300 centres, each joist at the centre of the span is braced to the concrete floor via blocks. The floor is quite solid with no bounce, the room size is 5m x 3.9m which is about 20m2. Between the 8x2 floor joists I have to place 100mm of king span to satisfy building regs.
I want to install electric underfloor heating and 60x60 super white porcelain tiles
could you please advise my questions are as following :

1 can I use 18mm external ply straight on to the joist, and tile on top?
2 having placed 100mm kingspan (b reg requirement is only 75mm I think) in the joists do I still need insulated backer board under the heating mats ?
also which electric heating do you recommend and want about this insulating paint?

 

[jimthetiler]

Either us 2x9mm thick board and overlap the joins or use the moisture proof chipboard flooring and stagger as well as glue the joints.
You will have no need for extra insulation if using 100mm kingspan.
Never heard of insulating paint,if it comes with the heating kit it is more likely to be a floor sealer which you will need.
I recommend sbr as a sealer as the tile adhesive will stick better to the board.
In my opinion I prefer the single wire as it seems less hassle to fix,any brand will do the job.

 

[rj1884]

Have a look at Ditra heat from schluter for the UFH, I've used it many times and is an excellent product and easy to install.

 

[swanman]

as above

 

[jamryd]

Hi, i know this is a long shot but i have moved into a house that has super white and need a few more boxes for extension work. The place where the previous owners got them from said they have been discontinued. Where did you get yours from? It was around the same period as when you posted this thread so hoping they are the same tiles.