Water UFH Advise plz guys - Tile Advice

[James]

Hi guys looking for some expert advise regarding movement joints and grout spacers !We have just finished my renovation we have a wet piped ufh with anhydrate screed all heating has been commissioned an ran up to max temps.I plan on using a str machine to remove all laitaince an prime an seal the screed then fix dirta with tm anhyfix The tiles are 600x600 porcelain I will be leaving all skirting an door frames off until It's tiled ,problem we are having is regarding movement joints ,trades on site are saying we won't require movement joints as we are fitting a decoupling membrane and are leaving perimeter movement all around the floors ??? I will upload a quick plan of the areas ,thanks for your time

 

[hmtiling]

British standard says min 3mm joint in heated floor but Imo you could get away with 2mm if your tiles allow.
You should,Imo, follow guidance on separating the floor into bays no more than 40m2 which can be done with colour coded silicone instead of unsightly expansion joints.
Hope this helps

 

[J Sid]

has the moisture content of screed been taken ?

 

[James]

Hi thanks for the replies,and yes moisture content is all within specs to tile,it has been down for about 16weeks an heating has all been run up to operating temps slowly each day ,once I have removed all laitaince I will do moisture check again I was thinking to put movement joints at each door threshold would this be ok ? Thanks

 

[Old Mod]

Doorways for sure, yes.
The only other place could be argued is a line between the top right of the staircase on the plan, over to the bi folds.
I've done one last Christmas that's very similar, did not bother with the one dissecting the living area and one year on it's still intact.
I know this because I was there sat morning tiling the cloak room.

 

[James]

Hi 3fall,ive been talking to a freind today who was on site an has said exactly what u have just mention

 

[James]

Do u think i will be fine with 2mm grout line ? And as for the movment joint what whould be best choice an also anyone recomend good addy for the porcelain to the ditra ? I was going to see what tm does as i have to order anhyfix but dont want rapid set as i am slow an fussy for levels an zero lippage .lol .thanks for everyones time am input

 

[hmtiling]

Standard setaflex for on top of ditra. Nice gear. Have you considered using Dural micro joint instead of a pre-formed one?

 

[J Sid]

no guarantee with Ditra if stuck down with anhyfix I believe, but many do...

 

[James]

Hi hm ,is that the micro that comes as a two pack an is applied in with mastic gun?

 

[James]

Thanks julian,can i ask what u fix ditra down on Anhydrite an have i had any issues with it bonding ?

 

[hmtiling]

Hi hm ,is that the micro that comes as a two pack an is applied in with mastic gun?

That's the one James. They'll colour match most grouts too.

 

[J Sid]

Thanks julian,can i ask what u fix ditra down on Anhydrite an have i had any issues with it bonding ?

I don't, you need to speak to there tec people and expect to be told a cement based adhesive