slate floor to prepare

[dave l and l]

hi
i have been measuring a job for a farm house and the customer is wanting slate flooring installed
she has god ditra matting which i have never installed before so i have phoned up read up and asked a couple of people about this and i am getting different info on certain things.
the floor is water under floor heating system with a screed on top
i have been told by ditra that i cannot use bal rapid set flexi. to fix the matting or the slate down. i have been told i need to bal rapid set for both .will this be right as i saw info on here and it seems that people use flexi al the time with this
i was going to prime the floor with apd then fix matting down with 4mm trowel the fix slate down with12mm trowel using bal rabid set
would this be right ??

 

[doug boardley]

that's how I'd do it dave, altho' I don't use bal.

 

[aphilp]

Firstly Dave you need to make sure that all your adhesives are suitable for use with underfloor heating.We would fix this project by using Ardex P51 primer, followed by the use of Ardex AF200 to fix the ditra matting using a 4mm vinyl trowel. We would fix the slate using Ardex X7R adhesive. We have never had any problems using this method.

 

[nybor62]

what type of screed is it firstly

 

[doug boardley]

it's deffo got to be a flexi addy tho.

 

[Andy Allen]

and flexi grout

 

[dave l and l]

i mostly use bal products unless a contractor supplies and i would use nicobond which i dont mind either
bal rapid set flexi with super flex grey i was thinking

 

[dave l and l]

i asked the customer the other day and she did not know what the screed was and the builder wasnt available to ask which is a pain
the people that sold the slate and the matting said bal or even tops tile flexi which i have been told was quite good for fixing i am not totally sure about that mind you

 

[Andy Allen]

if your going to use bal i would use bal ptb, its better for slate, and bal super fexi grey grout.

 

[White Room]

Is it a sand/cement screed or a poured version

 

[dave l and l]

its been poured

 

[dave l and l]

woman said it was poured in on one go. its not completely level all round but its not bad.

 

[dave l and l]

just out of wondering how can i tell myself what type of screed it is
also its 40 m2 through a couple of rooms do i need to leave space for expansion from floor to wall ?/
thanks for replies

 

[DHTiling]

just out of wondering how can i tell myself what type of screed it is
also its 40 m2 through a couple of rooms do i need to leave space for expansion from floor to wall ?/
thanks for replies

Ask the customer... this needs to be your first port of call before you even spec this job..

Come back when you find out what screed type it is.. either poured cement based or an Anhydrite screed.

 

[dave l and l]

hi its poured cement based screed. i asked her today and she said she had contacted the builder. i have tiled her bathroom wall and she is waiting for me to start floor . kind of trying to rush me but i have told her it will take time to prepare and for me to get all the info that i need before starting
thanks