View Single Post
Old 12-06-2017, 05:14 PM   #1
Registered User
Join Date: Dec 2017
Location: Ambler, PA
Posts: 22
Early 50s bathroom renovation looking for feedback

Hi there, DIYre new to the forum and never done a bathroom renovation or tiling job before

Im hoping to get some feedback on my bathroom remodeling plans, especially with the floor tile installation.

Im planning on gutting and re-doing my early 1950s second floor dormer bathroom (full bath). Im planning on replacing all fixtures, wall tile and floor tile (basically gutting to the studs and redoing everything). I realize this will be a big challenge. On the more optimistic side, Ive been doing a lot of research and even got myself a copy of the 2017 TCNA Handbook.
Regarding the floor here are my constraints (challenges) Im working with for this remodel:
  • Wife already picked out a 7/8 mosaic hex tile
  • We want electric heating under tile
  • This dormer bathroom is only a little over 7 high at the highest point, sloping down to a little over 6 at the lowest, so Id rather not lose any more headroom than I need to.
  • In addition to the low ceiling height, the hallway outside the bathroom (and the rest of the house) has 5/16 face nailed hardwood flooring, and theres already approximately a 1 step/threshold to the existing bathroom tile floor so, again, Id rather not build up the new tile floor height much more than it already is.

Some positives:
  • Its a pretty small bathroom (about 5x8) including the tube area (so only about 5x5.5 floor tile area)
  • The original tile floor is actually in really good condition. Only one small crack behind the toilet and is pretty level with just a slight drop (about 1/8) towards the tub. So Im thinking my joist support is probably adequate for what Im putting down.
  • The upstairs appears to have a 3/4 plywood subfloor. (The first floor has 1x4? T&G solid boards)

Heres my current plan for the new floor:

Using TCNA RH135 for interior floors with radiant heat over wood as a guideline, as follows:
  1. Rip up the old plywood if its too water damaged and replace with 23/32 EGP, glued and screwed to the joists
  2. Apply modified thinset and then 1/4 cement backer board screwed to the plywood
  3. Tape and seal (thinset) seems in backer board, let dry
  4. Prime backer board with SLC primer
  5. Attach Suntouch TapeMat to backer board with staples to secure the mesh and hot glue to secure the heating wire.
  6. Run 1/4 foam insulation band around perimeter, and seal all gaps with latex caulk
  7. Apply SLC (LevelQuick RS, or ES?) to a thickness of 3/8 to 1/2 to just cover over the heatmat level/feather, let dry
  8. Apply mosaic tile with modified thinset

Thoughts on the above? Any glaring admissions?

A few notes:
  • I using RH135 instead of RH130 because I want the Res 2 wet rating of course Im using SCL instead of Mortar but believe SCL is technically a modified mortar itself
  • Im using 1/4 backer board to save some height, but using the 23/32 EGP (instead of 19/32 allowed per spec) because Id like a little more rigidity. Does this make sense?
  • This should get me to around the same height as the existing tile floor (I think), at about 1-1/14 above the hallway floor maintaining the same threshold step-up I currently have
  • I would prefer to use Ditra Heat, but I dont want to chance the installation with the smaller mosaic tile
  • Im using SLC because it seems to be a lot less of a hassle and a better finish than doing two coats of thinset, and not that much more of a cost for a small bathroom
  • Ive read the library thread on SLC, and I see that one suggestion was to spray the primary over the heatmat, but I called Suntouch and they suggested not to prime the heatmat.

Thanks in advance for your help, suggestions, and feedback!
kickstart is offline   Reply With Quote