Water UFH UFH in extension, expansion gaps? Large format tiles?

[paul kitchen]

Hello everyone, we are in need of some sound advice on a dilemma we cant get 100% answers to, we are having a single storey extension and knocking out the back wall and dining room wall to form one large open kitchen/living area.
We intend to fit wet UFH to the new part of the extension but we are concerned about possible expansion/contraction between new slab and old slab leading to the failure of 1000mm x 1000mm x 6mm porcelain tiles which will cover the entire floor space including old and new!
We have been advised to use a reinforced screed and use an uncoupling membrane and flexible tile adhesive so the tiles don't crack or lift, do we need to lay an expansion joint between the old and new slabs too as this would ruin the clean effect we are looking to achieve?
Many thanks in advance,

Paul.

 

[paul kitchen]

Please see the plan for the new extension which at make things clearer!

 

[Qwerty]

Yes you do need one

 

[paul kitchen]

Thanks for the swift reply, can you recommend a slim line expansion strip to use?
Am I right in thinking the expansion strip just sits between the tiles and screeds and not the slab?

 

[Qwerty]

@Schlüter-Systems Ltd do some great profiles. They should run through all layers to the different screeds

 

[paul kitchen]

Thanks again, which uncoupling Matt and adhesive would you recommend to use with the porcelain tiles?

 

[Flintstone]

You do need an expansion joint where the two screeds meet. Try dural microfill, it goes in place of grout and they colour match it to any grout colour. Seamless

 

[Flintstone]

it sounds like a nice job, do you have a Tiler lined up ?

 

[hmtiling]

http://www.colouredmovementjoints.co.uk/movement-joints/movement-joint-types/micro-joints/

 

[paul kitchen]

Thanks for all the advice guys, what a great forum!
I don't have a tiler lined up yet but mentioned it to my builder who said he would do it if I wanted him to, the extension hasn't started yet but shouldn't be too long off, I wanted to arm myself with some facts at the outset to avoid some costly mistakes later on....
LocalTiler is this a job you would like to quote for, though I see you are quite a distance, Yorkshire?

 

[hmtiling]

Thanks for all the advice guys, what a great forum!
I don't have a tiler lined up yet but mentioned it to my builder who said he would do it if I wanted him to, the extension hasn't started yet but shouldn't be too long off, I wanted to arm myself with some facts at the outset to avoid some costly mistakes later on....
LocalTiler is this a job you would like to quote for, though I see you are quite a distance, Yorkshire?

No offence to your builder but this is most definitely a job for an experienced tiler. preparation is paramount with tiles of this size, especially when thin porcelain.
There's a section to list the job on here and some very qualified tilers too. Good luck!

 

[hmtiling]

Anywhere near Blackpool? I could tie it in with a trip home