Can I Tile this Floor?
Hi, I would like to put down slate tile, over an electrical floor heating system in my bathroom.
I want to know what I need to look for, prep for, and consider alternatives for, with my situation.
I have confidence that I can do this on my own and with my DH's brawn & brains.
Here is under my bath. the joists are 8x2 (but not quite, is that called nominal?). Unfortunately the joist are 21" on center. The diagonal flooring boards are 6" or so in width, and I presume 3/4"-1" thick as I estimate the thickness looking at a knot hole. These boards have a slight gap between them:
Top side - with the toilet removed it appears that there is 3/4" fir tongue & groove flooring over the diagonal boards. Then over the T&G there is an old linoleum floor. I don't want to add more than 1-1/2" to the height of my floor from the T&G fir flooring, preferably 1".
1) Will this floor situation be stiff enough for tile, as is, with the subfloor and fir flooring?
2) Is it recommended that 4 more joist go in between the 5 that are there. Currently there is 1 at each edge and 3 filling the middle, at 21" on center.
3) Do I add plywood atop the T&G to add more rigidity?
4) What is the depth of a slate tile + prep + electric underfloor heating?
5) When does the floor go in place? I will be relocating toilet, sink, putting in new tub, taking out plaster to insulate exterior walls, new electrical, etc.
Thanks for your consideration.