I'm replacing a 3/4" tongue and groove rotted bath floor, and want to put in
a tile floor. I've read different things in different books (and on
different web sites) in terms of how to do the floor.
What I need to know is the appropriate thickness of plywood to use (and
grade), and thickness of backerboard. Is 3/4" plywood and 1/4" backerboard
more than I need? The studs are 16" on center.
My goal is to use the thinnest option that will still do a good job (I'd
rather pay a little more for thinner underlayment if needed) to minimize
some potential problems with toilet height, drum trap height, and clearance
on the bottom of the bath door.
Anything will be firmer than the old rotten floor, but I want to make sure
I'm not setting myself up for a lot of grout issues if the floor isn't firm
Ours is 3/4" "structurefloor" an engineered OSB type product which is
attached to the 16" OC 11.5" TJI's by screws and construction adhesive.
Over that, the tile guy glued and stapled (used almost 2 boxes ~10,000
staples) 3/8" ply and then tiled. In some of the $500K- 1M homes in the
area, the General has him use a 3/8" dense medium grained chipboard (not
MDF, Hardibacker or OSB) the name of which I can't recall right now, over
the 3/4 stuff. The stuff is dense alright but has little structural
strength. You can snap it with your hands. It runs about $ 7.00 a sheet so I
went with the ply for a few bucks more for the added strength.
Been in the house for over a year and it works for us.
BTW, Some of the "experts" here said the 3/8 wasn't adequate. I'm sure
they'll sound off here.
Rudy once more attempts justification when he wrote:
Dear Rudy the Screwed homeowner,
Technically, you don't have a clue what you're talking about. Your
advice is flawed at best, and your ignorance shows every time you wail
about using plywood or chipboard as you attempt to justify the screwing
you got regarding your tile substrate.
<For the OP>
The purpose of an acceptable tile substrate is not to provide structural
strentgh. Structural strength is designed and built-in to the subfloor
prior to the finish floor substrate. The finish floor substrate needs
to supply an even, flat, and flex-free base for the tile or stone. The
TCA, tile manufacturers worldwide, and every engineer/ architect, tile
professional, etc, I've ever known or dealt with advises against using
chipboard, particle board, luan, most plywoods, etc for tile substrates.
<For the screwed homeowner>
$500K- 1M doesn't mean shit. To think that the price of the house (in
todays world) means one is guaranteed that non-inferior workmanship and/
or materials will be produced throughout the house is absurd. Once
again, your justification(s) for having an inferior tile substrate are
You're developing quite an inferiorioty complex about the inferior
substrate your 'General' stuck you with Rudy. I bet we'll never here a
peep out of you around here when the grout starts cracking. If this is
a tract development, you and your neighbors will be screaming class
action law suit very soon.
Always glad to help the ignorant, correct the morons that sound off
here, and support and add to those that give correct advice based upon
experience and knowledge of home building and repair. If that's an
'expert' then so be it and I am one. You're not.
Meantime, check out some decent attorneys and for pete's sake Rudy, quit
showing us your ass about this topic every time it comes up.
-end of conversation-
geeee I hope I gave the right advice, would hate to get flamed by
you. hahaha ... I do this type of work and yes I have had to
replace bath floors which were installed wrong by Jose and Jos B. If
the floor is not sturdy the grout will crack. 3/4" and 1/4" hardy
should be ok if the floor joist are 16" on centers.
"You can lead them to LINUX
but you can\'t make them THINK"
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