We just put in a Nuheat mat and Schluter Ditra in our masterbath, in the following order, from the wooden subfloor up: 1. Modified thinset 2. Nuheat mat 3. Modified thinset 4. Unmodified thinset 5. Ditra 6. Unmodified thinset (using a 1/4" x 1/4" square notch trowel) 7. Tile You should check the Schluter site because I believe that installing a heating mat over the Ditra will void the warranty.

We had this same situation. I did some research and found that you could either make or buy a "ramp" made for just this purpose. Ours was installed under the carpet pad and its made of a very heavy rubber. Tapered on the sides as well as the approach and it spans the whole width of the doorway. and about 24" long so you've got a nice gradual transition. It's absolutely a perfect solution. The carpet installers ordered it and I couldn't be happier. I'll try to attach a photo of ours tonight. Ours were similar to this as they were rubber http://www.johnsonite.com/WallBaseFinishesAccessories/FinishingAccessories/SubfloorLevelerSystem/tabid/813/Default.aspx But I'd suggested the website carpetshims.com to the carpet installers when we first realized the problem. The ones from caroet shims.com are wooden. I'd have been majorly unhappy with the look and tripping hazard of a step up/ uneven threshold.

OK, so I'm getting a million different answers from various tile contractors... Have put on an addition so that new space (with 3/4 inch interlocking plywood subfloor) along with an old area of the house (3/8 inch older plywood) will have a 1/2 inch layer of Veiga's climate panel installed. This is basically the same stuff as Uponor/Wirsbo Quik Trak. 1/2 plywood with grooves to put the pex tubing in. There is probably a little offset in levelness between the new subfloor and old subfloor. Anyways, I'm tryign to figure out what the best underlayment is. Including the heat panels, I will have a subfloor of 1 1/4 inch or 1 1/18 inch thickness. Manufacturer instructions then say 1/4 fiber cement board on top of that (glued and screwed). But now I have a contractor saying to forget about the cement board and go with the Ditra underlayment set in about 3/16 of thinset. The one area of tile will be about 500 square foot. I thought someone else had told me that Ditra was better for smaller rooms. Any insight on the best underlayment for tile on top of this heating system would be appreciated!!! Thanks in advance.

I posted some more info on installing Strata Mat on this blog post of mine. INSTALLING SMALL MOSAIC TILE OVER STRATA MAT Not sure why I thought I could use the Strata Mat with such a small tile but the repair I showcase works and is in line with what other uncoupling membrane supplier recommend for small tile installs over uncoupling membranes. In hind sight NobleSeal CIS would have been a better choice for that job. But the photos show how well the coverage checks can be seen during install. You get a nice visual confirmation. many of the Strata mat showroom displays are poorly built. They do not show proper coverage. I don't know why but the one here in Burnaby is a joke. Here is an install picture - this is my buddy's house. This picture shows the process - I have yet to smooth out all the thin-set. If you see the faint dark spots on the mat those are where the thin-set from below is locking into the top section through the breathing tabs. I love this a lot. the mechanical connection (be it ever so slight) from bottom to top. I have viewed effloresce lines in tile jobs before that appear to be on 3' centers. This could be from moisture migrating between seems of a waterproof membrane. This membrane allows even moisture migreation and better curing I think. This advertising photo is like the sample I see here in Burnaby If the product looks like this you are not really locking the thin-set 100% to the backer fleece. The bond is in this fleece and the reason why the Strata Mat is clear ish. Here is another shot showing a larger bathroom and more Strata Mat. Strata Mat is also a little wider than Ditra. This is an added bonus and allows for less seams. On the project shown below we used two kinds of Slate - both required modified thin-set for installation. So here the Strata Mat worked well again. Below the Strata Mat on this job is a electric floor heating cable from Cosco. All the thin-set to install it needs to cure - here again those little relief cuts allow for even curing under the tile install.