Remodeling a bathroom and using a contractor. He's a general and he's
going to do the tile install since he's cheaper than the tile guy. The
tub is installed with 3 walls surrounding. They've put up green board
around the tub and then his plan is to install wonderboard 6' above the
tub and then tile on top of that. Bullnose to cover the wonderboard.
I was at Home Depot today looking to see what kind of tile they had and
explaining the job to a guy there. He said that install method was not
to code and problematic. Condensation can happen behind the greenboard
and rot it out. He said the proper way to do it was no green board and
just use backerboard against the studs (same as wonderboard?) and tile
Been looking around the net and have seen sites showing both of these
install methods? Any advice. Been seeing info on using a membrane or
waterproof felt. Should that be used in either of these methods?
On 6 Feb 2005 00:06:32 -0800, email@example.com wrote:
Whooooops! You're going to have tiles set by a general contractor
because he is cheaper than using a tilesetter??? This makes no sense
whatever. I'm a general and quite apart from the fact that I am more
expensive than my trades, if I ever tried to set tiles or do
plumbing or even paint in my own house, my wife would ...well,
just say she would express her displeasure at the prospect of a poor
job taking forever to do.
This is not clear to me at all ... it sounds as if he is proposing
to put wonderboard on top of the green board. That's nuts and
wasteful, and worse, it won't work --- your tiles will be too far
away from the tub flange.
Does either of you know what you are doing?
It's a good idea to get technical advice from Home Depot. They make
minimum wage, are almost finished high school and once drove past a
The Home Depot guy is right --- use wonderboard (backer board,
Denshield, cement board, whatever) only. Green board is for the rest
of the bathroom. But he's dead wrong about why.
I don't mean to be raining on your parade, but this is nuts.
Think about it. A bathroom facelift is pretty elementary stuff. And
your guy doesn't know how to do it. You have a "contractor", yet
you're asking some goof at Home Depot and then a bunch of strangers on
a newsgroup what ought to be done.
This "general contractor" sounds more like a local handyman, whose
name you got off a supermarket bulletin board.
Assuming a standard tub, you are setting something like 80 sf. of
tile ... you should be able to get decent tile for two bucks a square
foot, and a top notch tile guy will charge you maybe four hundred
dollars to install it. You'll get a beautiful job.
Alternatively, you can pay someone less skilled three hundred bucks
and take your chances. The guy off the supermarket bulletin board
will cost you two hundred and fifty ... and then you can get the top
notch guy to tear it out and start over.
The best way to prep the walls is mesh and mud...This way the moisture is
absorbed into the grout/cement and evaporates out between showers. In my
last house I had both bathrooms, the entryway and the kitchen floors, walls
and counters done in this manner. Never a crack or loose tile even after the
California earthquakes....definitely your best bet.....good luck on your
Having done it wrong once or twice in my lifetime if this were a bathroom I
was doing, I would cover the studs with 30 pound felt apply 1/2" concrete
board of your choosing in the wet area of the tub.Finish and fill with
portland cement or durobond at a minimum. The remaineder of the walls in the
damp area would be green board.
The mud set suggestion is also a quality install but much more difficult and
expensive to install.
So if I understand correctly what you are describing, the contractor is to
put wonderboard, starting 6 inches above your tub, on top of green board? Or
is he putting greenboard only up 6 inches from the bathtub and then the rest
Wonderboard? Either way, it's stupid and nuts IMO, and possibly affect
(poorly) how your tile looks. Just use the Wonderboard/Cement board/Backer
Board/Hardi-Backer/etc. and forget the greenboard. I just finished
remodeling my bathroom and here is what I did on all three walls around the
- On the walls, ripped everything out to the studs up to 5 feet above the
tub (the greenboard that was previously used was ok above the 5 foot above
the tub so I took the shortcut of not going above 5 feet since Wonderboard
is 5' x 3'. I would have ripped everything out if I would have wanted to
tile all the way to the ceiling.)
- Covered studded wall with plastic. (Cant remember the exact pound
- Placed Wonderboard all around, on top of the plastic.
- Taped and mortared the seams (let sit for 1 day and then used a rock
sander to knock off the excess and to level.)
- I used an industrial strength membrane that you paint on (like the red
stuff you can get at HD) which was given to me by my friends father (he
would do the tile for me as a favor. He is a tile'er *not* a general
contractor). Let sit for one day.
- The final day my friends father came over, used thin-set and set the tile.
The membrane paint isn't necessary but it was free, and certainly couldn't
Well the HD person's advice is worth as much as mine is. It has nothing to
do with code but it does have to do with being problematic. Greenboard does
help prevent moisture from penetrating, however, it's only *SLIGHTLY* better
than regular sheet rock. This is why I'm remolding the bathroom in the
house I just purchased. (the previous owners let it get WAY too far.)
Forget saving $1 or $2 bux per sheet of green board Vs. using concrete
board. (Note that concrete board *does* allow moisture to penetrate however
it does not get soft and/or turn into mush.)
I'd drop your general contractor doing your bathroom and tiling. Spend the
extra money and get a tile person to do the work. Don't use a general
contractor. Some family members of mine did that and they are now sorry the
did. This time around they are using a tile person and the work he is doing
is a lot better and higher quality than the gen. contractor.
Good luck my friend!
Thanks for the replies. Ken - I don't know where you live but here in
San Francisco there's no way you'd find someone to do a proper tile job
for $400. 3 day job? That's $16/hour... no way.
But right now the green board is around the tub going up to the 10'
ceiling. Again, the contractor's plan is to install wonderboard on top
of the green board 6 feet above the tub and put tile on top that. It
sounds like that it would be better to have just the wonderboard
against the studs but is there anything *bad* about this install
method. The green board is already installed - should I rip it out? Ken
your remark about the flange is not a big deal. The wonderboard will
come over the flange and just grout/sealant/whatever at that join.
And yes I understand that mortar is the best way to do the job but I'm
not considering that here.
One thing I like about this plan is that the tile part will be 3/4"
from the wall giving a thicker look to the tile which I like better
than just a "surface mount" tile job.
You ought to at least consider a waterproof membrane between
the cement board and the green board. We just had a tile
job done and the order was (starting from the outside):
tile - thinset - mortar - aquabar - greenboard - stud
(Aquabar is a tar paper like material) The greenboard was
simply used as a spacer to aid in getting the right plane
for the wall.
I used to do it the regular way.
Got pretty good at it, too. Had a good 'eye' for
the mortar consistency, amount, bedding the tiles
in, everything. I'm just a home handyman, but one of
my tile jobs was sufficient to have people asking me
for the name of the remodeler that did it.
Problem I saw, though, was that the concrete-based
material was the weak link. You always had to assume
that water was going to get through the grout, behind
the tile, potentially into the wood. From the edge of the
tub, or by wicking between the tiles, or wherever.
So I started doing it differently. Nowadays, I use pure
white NONPAINTABLE 50 year silicone to bed the tiles
into place, and the same stuff to form what was previously
the 'grout lines'. Plenty between them, pressing the excess
outwards to be wiped off and used to bed the next one
Anybody can do it, and Greenboard is all I use, because
water is not going to be a problem.
I've described it in detail a year or so ago, doing the Google routine would
get it. The one I was discussing then was using
a tile pattern called "Arctic Ice". It matches with the silicone
so closely that it looks like it was made for it.
The tiles were less than a dollar each for the 35 I used, I
insulated the wall with Styrofoam first, to the edges of the
studs. When I put in the Greenboard, it was seriously solid.
Then the tile, as described. Took a day to do it, and was able
to stop for a break most any time.
Total cost for materials less than $100. And a few years later, nothing to
do but give an occasional squirt of "Scrubbing Bubbles" to bring it back to
looking like new. Never, ever a
hint of mold or mildew, no chilly walls, no grout lines that are looking
Did that answer your question?
I helped do a job many moons ago where we used the master set system. What
this was(note past tense) was a sheet of 9 4x4" tile mounted with 100%
silicone caulk. The sheets were then caulked together which supposedly made
a water tight system. This was in a food processing plant. I happened to be
back a year later when they were expanding and you'll never guess what the
wall looked like? The green board was rotted all to h*ll...
A properly installed ceramic shower will last many decades as long as it is
taken care of. Most mildue issues are due to improper ventilation. Keep some
air moving and your shower will dry and you'll have no issues...
Yeah, those were often pretty pathetic. Too many people wanted to just run a
bead, instead of being willing to waste some by pressing out the excess.
Couple of extra tubes of silicone, big deal.
A wall I did over 20 years ago is still lovely, and when they were doing a
bathroom remodel, that part got left alone.
Suppose the main thing is thinking like an owner, and excluding every
prospect of water entry.
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