Overkill - is this a wise layering for UFH?

[p4ulo]

So, I'm doing my own floor, and for the first time I'm putting wire underfloor heating over concrete.
Small bathroom, just over 2m squared of floor free for heating.
2nd floor flat, 60's build, thick concrete slab floor, few signs of old crackage.

Is this a good layering of products???

Prime slab with BOND SBR.
Combed out 8mm notch layer of flexible adhesive.
I've found some cheap cheap 6mm insulation boards.
WARMUP loose-wire UFH cable.
SLC to just cover wires.
4mm notch layer of flexible adhesive.
Schluter DITRA matting.
8mm Notch layer of flexible adhesive.
8mm glazed porcelain floor tile.
Phew.....!!!

I'm just worried this seems like a big layer of stuff for the heat to get through from the UFH??
Any advice. even if its just to say - YEAH, GO FOR IT! would be great, thanks.

 

[White Room]

What size are your tiles...

 

[p4ulo]

What size are your tiles...

15cm x 60cm

 

[Spare Tool]

Can't see the need for the ditra, I'd save your money on that and buy some better quality insulation boards

 

[White Room]

Can't see why your using Ditra with porcelain, the insulation sheets I would have gone for 10mm personally...maybe hight issues.

 

[Chalker]

I'm with whitebeam, ditch the ditra and use 10mm insulation board.
Don't forget to prime the insulation board with warmup's primer. (The tape will stick better)

 

[Stef]

Same as both of above, 10mm insulation boards if you can.

 

[rj1884]

Sorry to gate crash this thread but can I ask a question relating to this thread. If it was fresh concrete screed which has dried correctly would you use ditra Matt with electric UFH. I have this scenario on a job and I usually use the ditra heat but they've gone for loose wire. The tiles are porcelain.

Many thanks in advance.

 

[High Peak Tiling]

Just a personal preference but 'Yeah go for it'
I always use ditra when UFH is involved, even though the UCM not necessarily needed i have seen a few jobs with porcelain crack and blow grout due to expansion.
It does cost my customers more, but still gives off a lovely warmth to the tiles even using the more commonly used (in my case) 100w per m2 kits.

 

[rj1884]

Thanks for your response. Where in the stack would you lay the ditra. Would you lay it on top of the wires after they've been levelled over or would you lay the wires on the ditra.