Large format slate 1200 x 900 on UFH

[lewie]

Hi,

I've been asked to quote for over 200 m2 of large format slate 1200 x 900 on a concrete screed which has piped under floor heating. The largest area is 58m2. My thoughts would be to de-couple, expansion joints in largest area and between rooms and on perimeter. 15mm trowel and back butter individual tiles. But...

My customer is worried that the tiles may crack under expansion/contraction/movement and I agree that there's potential for this happening because of the very nature of slate.

Any advice/ideas ?

Lewie

 

[Stef]

If he's worried about them cracking then do as you state & decouple & that's that issue resolved.
That's a big bit of slate to fit, a four man lift..

 

[Dave]

Are you sure it's slate ? In that format.

what thickness are they and are they split or calibrated.

 

[Qwerty]

Sounds more like a slate hearth to me!

 

[widler]

If he's worried about them cracking then do as you state & decouple & that's that issue resolved.
That's a big bit of slate to fit, a four man lift..

4 man Stef?
Christ you need to eat more weetabix.
Laid bigger flags on my own

 

[Stef]

4 man Stef?
Christ you need to eat more weetabix.
Laid bigger flags on my own

I was being sarcastic m8, maybe 5. [emoji1]
We eat porridge wae Salt up here. [emoji123][emoji123]

 

[m3fitter]

probably 15mm mesh backed or could be 20mm uncalibrated ??

 

[widler]

I was being sarcastic m8, maybe 5. [emoji1]
We eat porridge wae Salt up here. [emoji123][emoji123]

SALT [emoji33][emoji27][emoji27]

 

[m3fitter]

SALT [emoji33][emoji27][emoji27]

cheaper than sugar ;-) Scotland = major heart attacks lol :lol:

 

[stone tiler]

10mm thick calibrated?

 

[lewie]

Uncalibrated from Mandarin Stone

http://www.mandarinstone.com/product/_/299/black-riven-slate-tile/?cid=19#.VC4wSmddWSo

A difficult one to price up methinks

 

[Time's Ran Out]

So it's 25-35mm thick flagstones!
How long had the screed been down and has the UFH been on?

 

[Dave]

What screed type is it ?

 

[m3fitter]

a sharp bolster comes to mind..... lol ;-)

 

[lewie]

It looks like a concrete screed

 

[Dave]

It looks like a concrete screed

What looks like might not be ... Have you ever come across anhydrite ?