fixing stone on to varsapane cement particle board over underfloor heating

[jonnyc]

I am about to lay stone 700x 500x 20 on an area of 120 sq mts.
floor make up is ,18 mm plywood screwed into noggins between joists.
25 mm kay metzeler insulation board with underfloor water heat pipes set within boards loose laid over timber.
then 25mm versapane cement bonded partical boards glued together loose laid over insualtion baord.
boards come presealed ready to receive flex cement based adhesive.

has anyone heard of this method or got any comments to make about how effective this would be.
i am also thinking of putting ditra mat on top.
Versapane boards do not warp or expand/contact in heat

 

[DHTiling]

Hiya..

The only problem i see here is that if that floor is not 100% flat then the system structure will deflect and with it not being a fixed structure then it will cause tile etc to crack and even de-bond..

I am not keen on these new systems when they say tile straight to them..when they are not even fixed to the substrate.