Andy the ufh goes underneath the ditra.
Pebbs[/QUOTE ↲
After alans disturbing news on weds night i decided to get on the phone to schluter and find out all i need to know which admitidley i should have before! Anyhow i have put off starting the job till monday and today recieved in the post a full spec sheet on ditra and ufh. I would just like to quote a little from that sheet....."for wire systems installed above schluter ditra please ensure that the cut back cavities are fully filled with adhesive and that an adhesive bed of aprox 2mm thick is spread over the mat and levelled, this is precautionary to prevent the wires touching the polythene mat. Once the adhesive has set the heating wires can be laid and tiles installed with a suitable notched trowel" so it seems i wasnt far out in the first place and have since wasted 2 days while this information came through. ↲↲
Re: the expansion joints just a little advice on that will be helpful. I was intending to put expansion joints in but i didn't know they must be directly above where different substrates meet, so when setting out the floor if i cant get a grout line on the diff substrates then i guess the only way is to cut a tile and place the two pieces back together with a spacer inbetween, so how with this job running through 5 rooms and the substrates not meeting in straight lines or running all the way across the rooms i will have to also cut tiles that actually don,t need to be cut to keep my grout lines lined up! How big duz the gap in the expansion joint spacing need to be, ie, how wide? Thanks Andy