1) I personally prefer to use the cable system from Warm Tiles (Easy heat). They have a layout pattern for uninsulated slabs.

2) You don't need a thicker bed over a wire system. A skim coat that just covers the wire is all thats needed.

3)I find the cable system less expensive and more forgiving in odd room shapes. The extra cost for the thinset skim coat and any height issues is negligible.

Great. Thanks very much!

1. I like NuHeat. If heat lose exists for whatever reason ... it effects all the same.

2. After the cable is installed I use 2 or more coats of medium bed mortar to level. I keep my mix as suggested by the manufacturer.

3. No ... level as required and let set. Install your tile when you're satisfied you have a level surface and protected cables.
Yes ... mortar does cost money, but the freedom to install the cables as you wish is a good bonus.
Otherwise ... use the mats.

Thanks again. I actually wrote "think" instead of "thin" in my 3rd question. Whoops. I'm sure you all got the idea.

I have a 1929 house. The basement slab is likely well past the point of cracking. That being said, would you guys recommend putting a Ditra board underneath, or would you slap the NuHeat directly onto the slab?

Ditra gives you that extra insurance.
You will have to skim coat over the Nu Heat if you plan on using Ditra. Ditra needs to be installed over a very flat substrate.

IMO ditra is good for problem situations. A well cured slab is not a problem situation if there are no unstable cracks.

Check the slab carefully and if you have any cracks bigger than 1/16th or cracks with vertical displacement on one side then you should be thinking about some sort of antifracture membrane.

Harry, so the order would be: skim mortar, NuHeat, another mortar layer or 2, then Ditra?

That's a lot of material for the heat of the NuHeat to work up through, isn't it?

Would the NuHeat mesh not act as a poor man's slip sheet if the slab below moves or cracks? In other words, would cracking be mitigated by the fact that the tile would be on a separation sheet (NuHeat) and not directly on the slab?

No skim coat ... just completely install your heating cables THEN apply mortar.
It's very important to make sure the cables are secured well and tight enough so they aren't flopping around.
Nuheat mesh?? Are you talking about cables or mat? I'm unfamiliar with NuHeat mesh.
NuHeat mats are not isolation membranes or slip-sheets. A slip-sheet should have an actual mortar-bed (1-1/4" thick deck-mud) built over top in order for it to succeed.

Install the cable and then embed into mortar so that it becomes part of the slab. THEN intall your isolation membrane over top and then your tile.
Someone else may offer other advice ... this is how I do it.

best stuff like the fellow mentioned earlier and the easiest is easy mat from costum you have to mortared down just like you do ditra and then wires on top works well

Bri, tell us what you think about Easy Mat from Custom!