Like so many, I have been looking through Harry's web-site for a while now and getting a ton of ideas. I have also been pouring over posts at John Bridges Tile your World site. I am a competent DIY'er (I worked for a renovation/construction company for 2 years) and have done a lot of my own renovations.

I have undertaken a basement bathroom renovation for my teenage kids, whom I let design the thing....they have big ideas.

I have removed the old moulded tub and surround unit, framed the shower, updated the plumbing and moved the drain, laid the mortar bed and installed radiant cabling (both on the bathroom floor and in the shower pan as Harry did on one job...I hope that wasn't a mistake!)

My plan is to do a kerdi shower and tile the floor. The floor layers up like this:

self levelling mortar 3/8"
"True Comfort" radiant cables
T & G plywood subfloor
poly vapour barrier
2" pink foam board insulation sandwiched between 2 X 4 strapping on its side
3-4" concrete slab

Do you think I need to spend the extra $ on Ditra or some other non-coupling membrane or should I be good to set my tiles right on top of the self levelling mortar?

I will post up some photos for feedback...especially about the cabling going up and over the curb and into the shower.

Thanks

PS...anyone near Collingwood with some Kerdi membrane to sell.....I need slightly more than the standard roll to do my job and I hate to spend the $!!!!

I think most of the heat wire manufacturers recommend an uncoupling layer between the SLC and the tile. If I had that much money and time invested in the floor, I'd go for the extra.

Are you saying you strapped the concrete floor with 2x4's? Why?
Where is the poly placed? With foam board, there is no need for poly except for strips of poly which should only be under the 2x4's.
Over a self leveling cement it is highly recommended to add a uncoupling membrane such as Ditra. SLC's are under a fair amount of tension as is without the heating. I would install the Ditra.

Why don't you just drive to Barrie and pick up the Schluter products from Tilemaster on Anne St. They will sell you what ever footage you need.

Thanks for the replies...I think I will go with Ditra and be sure.

RC...thanks alot for the Tilemaster suggestion...I would far prefer to do that than go to HD!

In answering your questions....the home builder, in 1993 tapconned pressure treated 2X4s on their flats to the concrete slab, as strapping between which they placed the foam board. They then laid a sheet of poly down over the whole assembly and attached the subfloor to the strapping

I'm amazed at how you kicked off this project. This year, I'm thinking about improving my bath, too, and this thread which you started truly inspired me. Thanks!

Schluter has some nice stair nosings to put in the doorway.

nice insights regarding the matter.