Bathroom installer doing first biggish floor , prep help - Tile Advice

[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

 

[On one]

Don't forget to prime the existing floor prior to laying the 10mm insulation boards.
Do you have access to a laser level ( to find the high point of the floor prior to pouring the SLC)
Work clean when you put the insulation boards down and the sticky mat UFH will stick better(some mats are better than others)

 

[Tony_C]

You could use a decoupling heat mat system like DCM pro or Ditra heat to kill two birds with one stone. This will also keep the heating wiring away from any danger

 

[Rcb]

Don't forget to prime the existing floor prior to laying the 10mm insulation boards.
Do you have access to a laser level ( to find the high point of the floor prior to pouring the SLC)
Work clean when you put the insulation boards down and the sticky mat UFH will stick better(some mats are better than others)

ok mate 10mm boards it is , I've got a laser level so will check high points, had a look the other day and its not that bad level wise to be fair . `probably gonna souped stupid now but it don't need any expansion gaps does it? obviously I will keep the tile off the wall around 5mm

You could use a decoupling heat mat system like DCM pro or Ditra heat to kill two birds with one stone. This will also keep the heating wiring away from any danger

Thats what I would of liked to use but the customer already has the mating so its gotta be this way unfortunately

 

[Just Rizzle]

some will disagre but when i did science at school heat went up not down and so in my opinion the insulation boards are an expensive wast of time and height build up
use ditra heat mat as easy and will decouple then lay tiles on mat if floor needs leveling screed befor instaling matting

 

[Rcb]

some will disagre but when i did science at school heat went up not down and so in my opinion the insulation boards are an expensive wast of time and height build up
use ditra heat mat as easy and will decouple then lay tiles on mat if floor needs leveling screed befor instaling matting

I hear what your saying , I have to lay the matting unde floor on this job though as customer has supplied it. What would you do matt to screed the decoupling over the top?

 

[Dumbo]

some will disagre but when i did science at school heat went up not down and so in my opinion the insulation boards are an expensive wast of time and height build up
use ditra heat mat as easy and will decouple then lay tiles on mat if floor needs leveling screed befor instaling matting

So you never covered thermal conductivity then

 

[Deleted member 49260]

some will disagre but when i did science at school heat went up not down and so in my opinion the insulation boards are an expensive wast of time and height build up
use ditra heat mat as easy and will decouple then lay tiles on mat if floor needs leveling screed befor instaling matting

Erm convection heat goes up, conducted heat goes every way including down - except a n insulated mat will limit the down bit. Just saying' and I did Phsyics (44 years ago )

 

[Just Rizzle]

Erm convection heat goes up, conducted heat goes every way including down - except a n insulated mat will limit the down bit. Just saying' and I did Phsyics (44 years ago )

about when i went to school cost over saving is minimal and wasteof money in my opinion

So you never covered thermal conductivity then

no but i can do maths and cost over saving will take over 10 yrs to pay for the boards as you will only run the floor for about 4 mths of the year you wouldnt have the matting on a day like today .

I hear what your saying , I have to lay the matting unde floor on this job though as customer has supplied it. What would you do matt to screed the decoupling over the top?

if you have the boards theirs on need to decouple as the matting dose that
stick down matts lay cable and tile any leveling do before laying mat

 

[Spare Tool]

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

Ray never once have I fitted ufh without some insulation under it, what's the point in heating the screed up at all?
The boards don't need screwing to a solid floor, stagger and tape over joints, personally would fix boards and ufh, level over wires then use a thin crackmat for uncoupling...

 

[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.