I'm a newbie and would really appreciate some advice on this project
that I have undertaken. I am going to try and give as much info as I
can, please ask me for more info if you need it.
My half bathroom is adjacent to the entry in my house (built in 1964).
Both floors were tiled previously but install was old and I don't think
very well done. I have removed both old floors and am down to subfloor
(I assume subfloor is the right term). Under the tile that was in the
half bath, was 1/4" plywood that had to be taken out, and under tile in
the entry was 1/8" thick board that was like really thick cardboard.
Seemed to be similar to what game boards (like Monopoly) were made out
What I would like to do is tile the whole area in the same tile,
hopefully tiling through.
What I was planning on doing is installing hardibacker over the subloor
and then tiling on that.
I understand that I should use unmodified thinset between backerboard
and subfloor, lay hardibacker, screw down, tape and fill gaps in
backer, tile over top.
I have lots of questions though. Have taken pictures to help show my
problems, and can take more if needed.
1. Can I tile from one room straight through to the other? Or should I
make it seperate and use a threshold?
2. My subfloor appears to be 3/4" plywood, can I install hardibacker
over this, what thickness should it be? What thickness is my goal
before laying the tile? I would like to keep it as low as possible to
avoid having huge floor height differences for adjoining rooms.
3. The subfloor is painted? Black almost to the edges, any ideas what
this was for and should I apply more of it?
4. There is one patch on the subfloor where this black stuff came away
with previous installation and there is now a slight depression,
What do I do to fix this before laying hardibacker or will the thinset
take care of it?
Also there are places where pulling the nails out from the previous
install and left little depressions in the subfloor. Will the thinset
take care of these?
5. Around the toilet in the half bath it looks like there is more of
this same damage, I haven't removed the toilet yet. (Previous install
wasn't tiled under it.) Will I have to replace this section of
The floor joists in my house are spaced 16" apart (I have a basement
and looking at the underside of the floor, there is this stamp on it
Is my floor strong enough to handle what I'm planning?
I apologise if this is too much to be asking and please ask me if
there's other things you need to know.
Thank you very much for your time.