DIY Home Improvement Forum banner
1 - 5 of 5 Posts

·
Registered
Joined
·
111 Posts
Discussion Starter · #1 ·
Hi. We are renovating a bathroom and put in a new acrylic bathtub in an alcove. They're putting tiles on the side of the tub as you can see.
The man built a wooden frame to support the sides of the tub as you can see in one photo. To that he screwed some backerboard and is now installing tiles.

My question is: It looks like the frame backerboard was put in slanted, because now to make the side tile perfectically vertical he's having to put in thinset to push it out a lot -- the gap you at the base of the tile is 1/4" - 5/8" deep.

Is this a normal process - i.e. you level out the tile by adjusting the amount of thinset you use or should he have made the frame and backerboard perfectally perpendicular to the floor.

Does it matter? Plus my wife says she's always understood that you should never leave big air gaps behind the tiles because they can then break easily if they're hit.

Please let me know your thoughts (if you know).
Thanks,
Water Automotive lighting Automotive tire Wood Asphalt
Asphalt Automotive exterior Gas Bumper Road surface
Wood Window Hardwood Flooring House
 

·
Naildriver
Joined
·
20,007 Posts
Difficult to see it all with the packing blanket in the way. Certainly the framing and cbu should be perfectly plumb to prevent it. However, tile is adjusted to a certain degree with thickness of thinset all the time, and when done properly it presents no problem. It does appear the installer is using dollops of thinset to set the large panels, which may be called for, but I would prefer a notched trowel base of thinset and back buttering of the panels to allow for proper placement, even with the slight angle. That way there won't be any hollows.
 

·
Registered
Joined
·
6,890 Posts
Some levelling with thinset is ok. However … i see 2 problems. Like Larry says, setting tile with blobs of thinset is wrong. “We always do it that way”. Well you always do it wrong. If the installer pushes back, make him show you on the tile manufavturers web site where they allow that.

Second problem. The acrylic tub is going to flex slightly when you sit on the edge to get in. Looks like the tile is tight to the underside of the tub rim, and tight to the floor. At a minimum the grout joints are going to crack, potential is for the tile itself to crack.
 

·
Registered
Joined
·
111 Posts
Discussion Starter · #4 ·
It's surprising that the frame wasn't plumb because he had previously straightened out all the walls, floor and ceiling. The house is 95 years old and everything was pointing in a different direction. Makes me think something 'settled' when the plumber did his bit.

And by the way, the fellow is from Italy/Albania and that is "the way they do it there". Tiles were manufactured in India so I wouldn't go by anything they put on the carton or instructions.

Thanks for your pointers!
 

·
Registered
Joined
·
8,603 Posts
There are basically 3 reasons to get full coverage on the back of tiles.

  • adhesion - at the end of the day, thinset is an adhsive, and the more you have back there the better it will hold
  • solid platform - as your wife says, technically any air bubbles or open spaces are weaker and could result in a broken tile
  • water resistance - you should always assume water can find a way behind your tile in a shower. An open pocket gives water a chance to pool up.

Having said all that, the first 2 are basically a non issue for me. It's not hard to keep tiles from falling off the wall, even with a little thinset like 1/3 coverage.

As for the strength of the tile, yes technically it's weaker but on a wall you'd have to hit it with a hammer to crack it. If this was a floor with people pounding on it, I'd be more concerned. (I installed an exterior patio floor tile years ago and afterward realized there was a big air pocket down there - I could hear it from the sound when tapping on the tile. Thousands of footsteps have gone over that tile and it's never cracked. This is tile with a weird random pattern on it, and I will say that I saved a tile that looks exactly like the one with the bubble underneath in case it ever breaks!)

It's actually the 3rd reason I'd be more concerned about. The tiles in front of the tub skirt - not so important. The tiles on the shower walls - I'd want as close to full coverage as I could get.

Regarding the out of plumb walls, it's unfortunate, but I have many times used extra thinset to fill the gap, when I couldn't or didn't want to reframe for one reason or another.
 
1 - 5 of 5 Posts
Top