I’m installing a new shower faucet that needs to be 3 7/8†to 4†from the finished wall. Because all of the plumbing has to be done before the wall is finished, I’m trying to guess how think my wall will be once the 1/2†cement board + 5/16†tile + 3/16†ridged mortar. The mortar will be screed with a 3/16†toothed trowel and I plan on buttering the back of the tiles. I would assume that the mortar will compress to about half of the thickness of the ridges making for a wall that is just shy of 15/16†thick. Is this a reasonable guess?
– Lyptus
Replies
That is a reasonable guess, close to 7/8".
My only question is why would you use a 3/16" notched trowel and then butter the back of the tiles? This insinuates that the 3/16" notched trowel is not leaving enough thinset on the wall and you are having to suplement it with additional thinset buttered on the back of the tiles. A two step process.
Why not just use a larger notched trowel on the wall and press the tiles in place without any back buttering needed?
Coverage is coverage. The tile doesn't care how the thinset got there....
When in doubt - test! Mix up a little batch of thinset and stick a tile or two to a piece of 1/2" substrate (does not have to be cement board - could use a plywood scrap) - measure thickness. Pull your tiles off, check for full coverage, wash thinset off of the tiles so you can use them later for your project.
Jim
Definitely helps to back butter larger tiles, especially if they have a waffle pattern on back. Even just a light "burn in" coat on large flat tiles or large natural stone can help with adhesion.But for typically sized tiles, yup, back buttering isn't needed at all.To the O.P., unless installing small mosaics or large format tiles, for regular tiles use a 1/4" notched trowel. That'll knock down to 1/8" thickness for the thinset.
That range is wacky. There should be more leeway there. I have NEVER seen a faucet set with such close tolerances to finish.
Somethings wrong.
"When the spirits are low, when the day appears dark, when work becomes monotonous, when hope hardly seems worth having, just mount a bicycle and go out for a spin down the road, without thought on anything but the ride you are taking." — Sherlock Holmes, 1896
>>I have NEVER seen a faucet set with such close tolerances to finish.<<
Probably a Grohe - their instructions are written that way -- then you go to install it and find out there is really an inch of adjustment.
As my 80 year old German plumber from "ze old country" says, "Damned Germans!"
JimNever underestimate the value of a sharp pencil or good light.
Ditto what Eric said, I have never seen a shower valve install with such tight tollerances. Actually, I've learned the hard way to not trust what the instructions say. I assemble the valve with the escussion, flange or whatever rests on the tile, then hold it in place to see how much leeway I have. Usually there is about 3/4" tollerance, and the instructions were wrong on more than a couple of occassions. You may want to do a test fit.
btw, on a related matter, I often see those valves installed loosely, depending on the wall surface to hold it tight, which never works. Such installations always end up leaking. I install wood blocking behind the valve, the spout and the showerhead, and use copper strapping to tighten it down, and mine never leak. Just thought it worth mentioning.
~ Ted W ~
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