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pfbz

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Discussion starter · #1 · (Edited)
I am a general contractor with a tile question... I've been searching/reading for an hour or so and have found much of the info I'm looking for (thanks), one question I couldn't get a clear answer on...
What is the maximum recommended thickness for thinset?

Is 1/2" height after setting acceptable?


I understand that thinset isn't designed for leveling, but there is a minor amount of leveling that needs to be done sometimes. On a small job, it's tempting to correct with thinset.

So after setting, what's your recommendation on the maximum amount correction you'll do with thinset before going to a leveling compound?

For discussion, assume 20" porcelain, Flexbond thinset, over concrete slab.
 
There's some stuff called self-leveling mortar/concrete. You SHOULD level the floor prior to doing anything other than carpet.

Tempted to level 20" tile with thinset? You'll be back!!!
 
CScalf started and ended with a :thumbsup:. I hope that doesn't mean he thinks using thinset under those circumstances is OK. :w00t:

The directions clearly tell you the 'beat in' thickness can be NO thicker than 1/4" with that thinset as well as all others with the exception of medium bed mortars.

The only smart thing however is to fix the floor before you start setting tiles. Otherwise tell the customer to,

a: expect the job to look like crap.
b: choose a much smaller tile.
c: get some one else to do the work 'cuz you are not interested in doing junk work.

The floor should be "flat within 1//4" in 10 ft. AND 1/16" in 12" of the required plane."

This is a ANSI spec for concrete floors. You need the same for wood floor of course.

When the tiles are large and/or smooth and/or shiny, I recommend the requirement be within 1/8" in 10 ft.

Jaz
 
I agree. Especially with large format tile, that floor needs to be just as flat as humanly possible BEFORE you open the first box of tile, or you'll be fighting it the entire time you're setting, and 9 times out of 10, you still won't get it right.
 
The terms "self level" and "thinset" don't belong in the same sentence under circumstances such as this. "Self levelling" with thinset CAN NOT BE DONE.

The higher cost of using real self levelling compound is well worth the extra money you pay for the product. You trade time fixing and grinding and fixing and grinding thinset for the price of the self leveller that would have the task done in a matter of minutes.:)
 
I set thousands of feet of random pattern slate on a job, they were 24" by 24", 12" by 12" and 12" by 24". Not only that, the 3 sizes were different thicknesses. In some places the pad was an 1 1/2" low. I cant remember the brand name of what I was using to set the stuff but the slate came out dead nuts perfect, yeah I used pallets of it though. Lot of work, yes.
 
The terms "self level" and "thinset" don't belong in the same sentence under circumstances such as this. "Self levelling" with thinset CAN NOT BE DONE.
Yes perfect tile setting can be done with rough floors, there are circumstances where it has to be done. This is what separates the men from the boys.

There is no "self level" period. Unless youre doing production level crap work. I cost at least twice as much as your average tile setter, and it shows. You want to pay for it, you'll need a automotive type feeler gauge to find problems in my work. Total BS that the floor has to be leveled first.
 
WWFB-- although I know what you mean, and I agree with you to an extent, for all intents and purposes, most of the time, the floor doesn't have to be quite that perfect, unless you're using polished or honed stone, or rectified porcelain. You can do a MORE than adequate job with SLC for most work. As for the material you were talking about up above, could it have been Laticrete's 226 Thickbed mortar mix? I've used that before, and although it's expensive as hell, when you don't have a place for mixing sand and cement, it's a lifesaver! :thumbsup:
 
A bit dated.
But I watched a setter using mortar to level 2x3' granite. He back buttered with thin-set and layed them on about 1" of mortar which he said was 1/2 when he started. He then pulled it back up and added more. Looked like a PITA but it was perfectly flat.
 
I guess I don't know why anyone is bothering to answer a question that is a little suspect in the first place. No introduction, no location, no real name just what seems to be random letters.
 
Discussion starter · #18 ·
I guess I don't know why anyone is bothering to answer a question that is a little suspect in the first place. No introduction, no location, no real name just what seems to be random letters.
This (obviously) isn't a forum I frequent often, but I did (and do) appreciate those that helped me out two years ago, when I asked the question....
 
I guess I don't know why anyone is bothering to answer a question that is a little suspect in the first place. No introduction, no location, no real name just what seems to be random letters.
The answer to the OP is...yes. A long as you "burn" the substrate and keep your "lifts" around 6mm (1/4') Go with 317 or Kerabond...if you're going to build again, then "scratch" after flat trowelling. 24 hrs between "lifts" and you're golden...just don't try to build more than 19mm (3/4") using this product.
Personally? I do a mudbed if it's outside of these parameters. The cost of SLC will kill on something like that.

Cheers, Ron
 
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