Bathroom installer doing first biggish floor , prep help Page: 2

[Rcb]

Hi, been fitting bathrooms and tiling them for years now but never taken on solely tiling jobs so the floors have never been over 6-7 meters.
So I've got a kitchen / dining room to lay 400 x 400 ceramic tiles , its a screed floor thats been levelled off around 3 months ago. Ive got to lay electric under floor heating as well.
The floor size is 28 metre square and the customer wants the whole room tiled before kitchen is installed (so big empty space)
So my plan was thermal boards fixed with tile adhesive and screws and washers , will a 6mm do to stop the heat going down instead of up through tile, or does it need to be a thicker board , if so what size
Then I was going to put electric under floor down , sticky matt type
Then self level over the top of cables
Then lay a ditra matt / uncoupling system over the top
Then lay tiles .
Is this ok ?Or are there any easier or better ways of doing this ?
Any hints or tips I should know before doing the big floor?
Thanks in advance for any info

 

[Andy Allen]

Definitely use insulation boards.
Just stick them down on a screed.
Fit the heat mat, level over the top.
Personally I wouldn't bother with a decoupling mat unless I was fitting natural stone......or anything under a grade 4 ceramic....

 

[Tile Shop]

Told myself I wasn't going to do this anymore, but.....

20 sqm floor with 16sqm heated area at 150w per sqm, based on being run [for the average household] throughout the year, 2 hours per day (more in winter, less in summer) = running costs of £245 per year when insulated (based on 2.1p per sqm per hour). Due to the heat distribution on an uninsulated floor, it will need to run at "approx" double the power to continuously raise the surface to the required temp, rather than heat up in 30-45 minutes and maintain a constant heat. This puts the running costs up to approximately £490 per year, £20.43 per month of which is wasted energy.

20sqm of insulation boards inc fixing materials, taping and labour = £450 approximately? So the insulation pays for itself within 22 months.

So unless you envisage your floors having to be ripped up and relaid in under 22 months, waste of money? My arse!

 

[Steve6690]

minimum 6mm insulation board then Ditra heat, then tile it. Yes it's pricey but less potential points of failure. As they've supplied the mat though,insulation board stuck down, mat, slc, ditra, tile , not forgetting to prime where needed.
You asked for any other hints or tips so I apologise in advance if I'm teaching you to suck eggs, but don't lay electric ufh under fixed furniture and consider door mats etc as well.