Old House Reno: Two Bathrooms, Many Problems to Solve

[cx]

To the subfloor is sufficient, Matt.

[MesaTileworks]

Originally Posted by cx

In our Liberry you'll find a good article showing what I consider the very best method of installing that second layer.

CX, do I understand the diagram in the article you linked correctly to mean that 1) the second layer of plywood is set parallel to the first (both at a right angle to the joists), 2) that between the joists, the seams of the second layer are placed at 1/4” the joist span, and 3) the joints running the other way (the long ends of the sheets) are placed as far away from those same joints in the first layer as possible?

[MesaTileworks]

Is the aforementioned “cleavage membrane” roofing felt or some other material?

What about a similar situation but on a concrete slab? In that instance the lath can’t be stapled down... would one still use lath and a cleavage membrane or some other combination of materials?

[cx]

Roofing felt is fine. Over concrete you customarily eliminate the membrane and lath and bond the deck mud to the concrete with a slurry of pure Portland cement or thinset mortar.

There is an unbonded reinforced mortar method over wood or concrete, but not normally used for a shower floor.

My opinion; worth price charged.

[MesaTileworks]

Ah, interesting. Slurry would be a thin layer of cement mixed very wet, which goes first, then deck mud? Do you have a link to a breakdown of that procedure?

[MesaTileworks]

Picked up a bracket and figured out how to carve out the framing so it would sit flush. No more wiggy pony-wall!

[MesaTileworks]

Circling back around and getting ready to install the roofing felt and lath for the mud pan... am I correct in thinking that it’s OK that the staples securing the lath will penetrate the roofing felt? (i.e. the felt is there to stop the subfloor from absorbing too much moisture from the mud as it cures but it’s kind of a secondary thing and obviously not a waterproof membrane so the staples are OK?)

[cx]

It is as you describe. The staples are OK.

My opinion; worth price charged.