can you double tile over ufh

[davidpatullo]

tiled a floor today and the lady doesn't like them (she picked them)
tiled on top of a ufh system.
does anyone know if i can go directly on top of the tiles?
will the ufh conduct heat through both layers?
thanks.

 

[Del W]

How thick are the tiles ? and how far down is the UFH ? Can the floor take the weight of more tiles,addy & grout ?

 

[davidpatullo]

9mm thick tiles. tiled directly on to the wire about 10mm bed the floor should take the weight. floor was megga bumpy helps her and me not to rip up and start again.

 

[Del W]

Floor was megga bumpy ???

 

[trevortine]

Dont do it. They will heat yes but will take longer and never be as efficient as with one layer, what type of adhesive did you use to put them down? Even a rapidset can still be lifted easily after a short time setting, were the cables in screed? Personally I would never tile over this but if you have 20 years exp then its your call, and customers pocket thats gonna hurt for changing her mind!

 

[davidpatullo]

i agree. still a nightmare it was bal rapid flex i used, she phoned me tonight, after i had left the job,
tiles will be solid tomorrow morning. thanks for replying. first time using the forum.seems cool.

 

[trevortine]

Great forum David! Customers are a nightmare eh! But we all need them! I would just stress the fact she picked them, by the morning she'll probably love them!!

 

[Stef]

Thats a thick bed for Bal flex, up to 12mm over localised areas it states.

Personally i would have put that in a self level screed, done 1 today, but it still doesnt help you.

I would rip that up & start again.

 

[davidpatullo]

i couldn't use self level screed as i used a primer for conducting heat that insisted i didn't screed over it.

 

[nybor62]

as you did,nt slc over ufh i would say imo rip out doubt you will save the ufh
what substrate was ufh laid on , i dont understand why you could,nt slc over the primer maybe im missing somet

 

[davidpatullo]

first time i have used this type of primer as well. might be a new material. The woman supplied it. it stated on the bottle not suitable for sl screed. normally i use the sl screed method. dough.

 

[davidpatullo]

the primer was like shiny white paint, obviously to conduct the heat

 

[davidpatullo]

oh it was an 18mm plywood sub
floor

 

[Stef]

I would have stuck Hardie or Wedi etc on top of that & Self Levelled, no need for fancy primer.

 

[nybor62]

as above thats why i asked what substrate was

 

[AliGage]

Sounds like a "warmup" UFH kit.

 

[Muse2k8]

All you can do is explain to the customer the options and why, give her your recommendations and let her decide. Although ultimately you don't want her to tell other people that you put in UFH and it doesn't even warm the tiles up!