I got tiles, premix thinset, "blue board" water resistant sheet rock in preparation to replace a section of tiles in my shower stall. The guy in that dept where I got the stuff at Home Depot insisted I don't need spacers for the tile, that shower stall wall tiles are supposed to be butted up against each other.
All the "how to" videos I see on YouTube show the use of spacers for setting shower stall wall tiles. You think this guy just didn't know what he was talking about?
If he worked at Home Depot it's pretty much a given that they're talking out of their ass. Sad, but true.
The wall tile do indeed have lugs on the sides that space the tile a bit, but there are problems with having such a thin grout line. It leaves no room for error and if you run off even a little bit laying the tile it will only get worse as you continue. It also makes it a pain in the ass to regrout should that ever be necessary. Too thin of a grout line is as bad as too big of a grout line in wet areas. Go with the spacers - 1/8" or a bit more is about right with 4x4 or 6x6 tile.
BTW, blue board is for plaster, green board is moisture resistant and should _not_ be used in a shower.
R
They told me that this stuff - actually kind of a purple color - replaced green board and is what you would use in a shower stall.
It's made by Gridmarx, says manuf'd to ASTM Standard C1396 and CSA Standard A82.27
If not this, then what should be used in a shower stall?
I pulled this off one web site:
"Backsplashes, Shower Stalls & Tub Walls Water resistant greenboard sheetrock should not be used for walls that will be subjected to heavy amounts of moisture. This includes but is not limited to, shower stalls and tub enclosures. Greenboard is water resistant but not water proof and will disintegrate if it is exposed to excessive amounts of moisture. It no longer is approved for use (ANSI A108) as a wet substrate. Depending on moisture conditions, this product is acceptable for use as a ceramic tile substrate in residential backsplashes and bathroom wainscotings."
I'd never heard of the stuff, but, again, the HD guy seems to have been talking out of his ass. Here's the Gridmarx manufacturer's web page - has nothing at all on any water resistance properties.
My personal favorite is Wedi board. It's very easy to work with, it's light and it's waterproof. There are also a bunch of different backer boards, such as Durock, Wonderboard, Hardiboard, DensShield, Fiberock, etc.
Do some more research on what you have. Unless there is another product also called Gridmarx that is very water resistant, don't use what you have.
R
use concrete board and mortar all seams before tyling
A) The term 'concrete board' will confuse some people. The normal name for the type of product you are referring to is a cement backer board.
He states he's replacing a section, and seems to be detail oriented, so he probably wants to match what's there.
He could use anything for spacers horizontally, vertical isn't much of a problem to eyeball.
The other problem with thin grout lines can be filling the space all the way to the substrate. An unsanded grout of lighter than usual consistency would be my choice.
My theory is that most modern grout jobs fail due to failing to dampen the joints before grouting, followed by failing to fill the joints, and/or poor basic construction.
Which brings me to failed grout. The only reason I know of that grout should fail is excessive flex of the substrate. In that case, no grout job is going to last.
Any such major tile repair should be carefully evaluated against complete replacement, and I wouldn't suggest the former be tackled by homeowners, except that the chance of finding anyone more qualified is exceptionally poor.
There are tons of little tricks a "real" tile mechanic employs that nobody told the clerk at HD. In this example it might be beating in the new tile from a base on the existing tile, or recessing the new substrate a hair and building it up with thinset to make it all come out flush, or washing out the corner joints just a hair to leave a little more room for caulk, if you think it's necessary.
All depends on your expectations of the finished product, I guess. A good tile job is expensive, a homeowner can get comparable results with due diligence. -----
- gpsman
I've always figgered that if the 'experts' at the big boxes were so smart, they'd be installers making far more money than at the store.
Right. I didn't address that and I should have. I should also have mentioned that unless you have the exact same tile from the same manufacturer the tile will probably not match exactly. If it's a little bit small you can get away with it, but if it's a little bit big and the OT (original tiler) just butted the tile against each other there will be a problem.
I like the round-square-round toothpicks as spacers. I also like to chew on them. ;)
Or using too much water when cleaning off the excess grout.
I usually point people to the John Bridge tile forums. Lots of good information and advice over there.
R
Bad move. Premix thinset and "blue board" are not intended for wet applications. For this application regular thinset and "hardibacker", or equivalent, is a must. Neither are difficult to use and will last.
As others have said, if the tiles have the bumps on the edges spacers aren't required. I'd use them anyway.
Since he didn't tell you that "blue board" was a waste of time and money, certainly.
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