Limestone floor with electric underfloor heating - advice?

[Unregistered]

Hello
I'm looking to lay a limestone floors of about 24m3, using large stones (900x600x20). The existing floor is concrete (35 years old, not newly laid), and the plan is: adhesive, 10mm marmox boards, heatmat, levelflex fibre compound, then (about a week later) tilemaster adhesive (standard set) and the slabs. Does this sound okay, as after reading some of the other forum posts it sounds as though cracks could be a problem?
Thanks!

 

[Ajax123]

Always use uncoupling membrane with natural stone tiles.

 

[Unregistered]

Thanks. How much does this usually cost? Is there a recommended time to leave the levelling compound 1st?

 

[White Room]

Some self leveling componds can be 3-24 hours, read manufacturers instructions...

 

[Unregistered]

Will do. The supplier said it should be okay after 24 hrs, but I didn't know if it would be worth heating up/ cooling down the levelling compound before laying the stone?

 

[Rookery]

Drying time is usually dependent on the thickness but as you're only going over a heat mat, say 4/5mm, 24 hours will be fine for the SLC. As its a natural stone I'd include an uncoupling membrane in the spec as Ajax says. Once the tiling work is complete, the floor needs conditioning correctly by warming and cooling gradually. There are plenty of threads on here giving the details.

 

[Unregistered]

Thanks very much for the help