mixed substrates

[kilty55]

hi all,read up on this a few times but have not had to deal with one yet until now

i havea kitchen/utility to tile floors and the kitchen is floorboards and the utility concrete.....would you advise uncoupling it and also an expansion joint at the door threshold? 18mm ply going down with a 6mm cement board on top and will have to screed the other floor up to meet the height

 

[DHTiling]

Re: mixed substartes

mixed substartes..?????

 

[doug boardley]

Re: mixed substartes

I'd use hardie over the floorboards Jamie, expansion joint where the different substrates meet, and if need be slc the concrete up to the same level.

 

[kilty55]

floorboards are not great shape to be honest doug,i usually go the cement board route too but thought it would be best to use ply 1st then over board with the 6mm boards what do you think

 

[kilty55]

would you still just do the expansion joint and not bother with the membrane doug?

 

[Aston]

how big is the area of the floor?

 

[kilty55]

hi ed,kitchen is 18 metres and utility is 7 metres

 

[Aston]

i'd personally just go with the expansion joint..if the concrete has been down for a while and fully cured.
if you really fix the new 18mm ply down and the 6mm backerboards then over that sized area, it should fine imo

oh, what tiles are going down mate??

 

[kilty55]

gemini black polished porc nano 600 s

 

[doug boardley]

sorry Jamie, I got sidetracked.. any ufh going down?

 

[kilty55]

no ufh mate

 

[Aston]

hi jaime, i'm sticking with my origional advice mate ;0)

 

[kilty55]

cheers guys
great advice as always

 

[doug boardley]

as per Ed then Jamie

 

[Alan.P]

I would take up the floorboards, fix the ply down with all prep 'obviously' to keep the height down, and use a decopler up to concrete floor where it would meet an expansion joint.