Hoping to get feedback regarding what you consider the BEST sub-floor for a porcelan tile floor that will be layed over three contiguous rooms (enty foyer, kitchen and powder room ) Currently the foyer has a slate floor over a mud sub floor ( plywood was dropped below the top of the floor joists appears as if 2 inches) the rest of the 500 sq foot area has typical 2 layers of plywood. As I indicate above I want to lay same tile from entry foyer through into the kitchen and into a power room . Concerned with “joint” between mud subfloor section and plywood subfloor section if I use a cement board over section that currently has a plywood sub-floor.
A couple of tile retailers that I have consulted with feel a cement board or even plywood sub-floor are sufficient. I am concerned theywant to do a simple jb and not have to deal with laying methal lathe and pouring a 1″ mud floor. Too time consuming. Are they trying to get in and out and not concerned about future issues? Or is cement board or plywood as strong and stable as a 1″ mud floor?
Replies
nj... assuming your framing is correct for deflection.. a good tile subfloor will be 1 1/4" .. ( typical 3/4 subfloor & 1/2 plywood underlayment )
a metal lath/1" mudfloor is a pretty old spec...
there are some tile guys who post here who can give you more advice... ..
me.. in the joint areas.... i'd be looking form some isolation membrane
U want quick and easy ... and very good ...
notice I didn't say cheap?
build up the ply area with ply to be flush with the mud bed ....
then Ditra over the whole thing.
There's your backer ... and uncoupling membrane ... and crack isolation ...
all in one.
http://www.schluter.com/english/products/2002/sectionf/ditra/601-index.html
depending who's laying it ... the ease and speed of delivery/transportation/installation can help off set the materials costs ... roughly around $2/ft sq.
Jeff
Buck Construction
Artistry in Carpentry
Pgh, PA
Thanks Jeff. I have looked into Ditra. Their website is very informative. Video demo has convinced me that your suggestion is my best option. Now I have to convince the contractors.
might be a new product form them ....
but it's a great product and they'll be glad U made them try it.
Just pay attention to the bonding thinset ....
I'd ask my supplier .. or contact Schulsters(sp?) direct to see what's best to go over both ply and concrete ... they usually recommend an unmodified under ....
but I've used modified under where I thot I wanted more "stick" ...
just gotta let it "cure" for a longer time so ya don't have excess moisture screwing up the grouted end result.
If it's a whole house remodel .... lay the ditra .... hit the other work ...
then come back a week or so later and lay the tile.
Jeff Buck Construction
Artistry in Carpentry
Pgh, PA