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Thinset trowel size

FastEddie1's picture

Installing ceramic tile on a concrete slab.  Chipped off the old tile and thinset, but the result left a less than perfect slab.  The tile will be a pattern of 6x6, 12x12, and 18x18.  What size trowel would you recommend?  I'm thinking 1/4x3/8 will work, but it's on the small side for the big tiles.  I havre a 1/2x1/2 but that seems big for the small tiles.


 


Whenever you are asked if you can do a job, tell'em "Certainly, I can!"  Then get busy and find out how to do it.  T. Roosevelt

I'm sorry, I thought you wanted it done the right way.

(post #95652, reply #1 of 12)

First get your slab smoothed up.  Get a cup grinder for your 4 1/2" grinder (diamond) and grind off any significantly high spots.  That won't take long.  these grinders are not real cheap but you will be very glad you got it (or you can rent such a rig if you won't need it often).  Then treat low spots or chipped away areas with a coat of thinset troweled smooth and let it set.  Now your 1/4" x 3/8" trowel should be fine.

(post #95652, reply #2 of 12)

I spent two days ... literally 16 hrs ... chipping thinset off the slab with my Bosch Bulldog and a 1-1/2" chisel.  It actually comes up fairly easily, but makes a heck of a mess.  Fortunately the HO really, really wants the new tile, and is being a very good sport.  I hung visqueen in all the openings and set a 36" fan blowing out the back door, and it still covered most of the place in dust.


 


Whenever you are asked if you can do a job, tell'em "Certainly, I can!"  Then get busy and find out how to do it.  T. Roosevelt

I'm sorry, I thought you wanted it done the right way.

(post #95652, reply #3 of 12)

go to the rental yard and get a concrete grinder ...


looks like a floor buffer ... but has rub blocks wedged under there ...


you can either hook up a hose ... or just give a squirt from the hose ... or dump a bucket .. to keep the floor wet.


very little dust .... most any basement floor could be knocked down for the 1/2 day rental ....


takes longer to mop up the mess than to actually "flatten" the floor ...


 


if it's old thinset ... it'll work wonders.


 


and ... use a big notched trowel.


 


Jeff


Buck Construction, llc   Pittsburgh,PA


     Artistry in Carpentry                

    Buck Construction

 Artistry In Carpentry

     Pittsburgh Pa

(post #95652, reply #4 of 12)

or dump a bucket .. to keep the floor wet.  Sometimes you guys are soooo much help.  It's a kitchen floor, with carpet on one side and wood floor on another side.

Whenever you are asked if you can do a job, tell'em "Certainly, I can!"  Then get busy and find out how to do it.  T. Roosevelt

I'm sorry, I thought you wanted it done the right way.

(post #95652, reply #5 of 12)

Tell HO to do it & call you when she's done.


Joe H

(post #95652, reply #6 of 12)

I thot we were talking about a concrete floor here ...


 


what the hell happened ...


which thread am I in???


 


Hey .. I got an idea ... don't pour no water in there ....


 


Jeff


 


 


Buck Construction, llc   Pittsburgh,PA


     Artistry in Carpentry                

    Buck Construction

 Artistry In Carpentry

     Pittsburgh Pa

(post #95652, reply #8 of 12)

We are talking about a concrete floor.  But dumping a bucket of water on it to keep the dust down won't work, cuz the two adjacent rooms are finished with wood and carpet.


I got it worked out ... I trowel the thinset with the 1/2" trowel, then when I get to the areas that receive the 6" tiles I re-trowel just that area with the smaller trowel.  The 6" tiles are only about 20% of the area, so it's not a problem.


 


Whenever you are asked if you can do a job, tell'em "Certainly, I can!"  Then get busy and find out how to do it.  T. Roosevelt

I'm sorry, I thought you wanted it done the right way.

(post #95652, reply #9 of 12)

I'd just stick to the 1/2 all over ...


do a test piece with the 6 incher's ... trowel it down ... lay ... set .. then pull.


Check the back ... bet ya have enough ...


or ... I'd trowel the whole floor 1/2" ... and back butter the 6'ers with a 1/4" light.


I think you'll have an easier time getting them all at the same height that way ...


 


then again ... we're just sticking some flat stones to the floor ... trial and error ...


what ever works quickest and easiest is the word of the day ....


 


report back ... I may need to know that part in advance someday.


 


Jeff


 


Buck Construction, llc   Pittsburgh,PA


     Artistry in Carpentry                

    Buck Construction

 Artistry In Carpentry

     Pittsburgh Pa

(post #95652, reply #7 of 12)

Our tile guy told us that the only good way to check the trowel size is to lay one of the tiles, pull it up and look at the coverage that you have. If the tile is not completely covered on the back, try the next size bigger notch. You want to use the smallest trowel that will give you complete coverage.

(post #95652, reply #10 of 12)

Ed, no one can say for sure.

With that large format, and a combination of sizes, I think I would start with 3/8" and look for good coverage and a flat installation. If that is not working, you may have to back butter or move to half inch.

Try to get all that cutback (leftover thinst) off, or at least as much as you can.

Regards,

Boris

"Sir, I may be drunk, but you're crazy, and I'll be sober tomorrow" -- WC Fields, "Its a Gift" 1934

Regards, Boris "Sir, I may be drunk, but you're crazy, and I'll be sober tomorrow" -- WC Fields, "Its a Gift" 1934

(post #95652, reply #11 of 12)

Here's two pics of the unfinished job.  One is the splash behind the cooktop.  It uses mostly 6x6 tiles with some decos.  The other is part of the floor, which uses the same 6x6, plus 12x12 and 18x18.  The floor is not grouted yet.  It's a little hard to see, but none of the tiles have straight edges, which makes the layout tough to keep straight.  the pattern doesn't help either.


 


 


Whenever you are asked if you can do a job, tell'em "Certainly, I can!"  Then get busy and find out how to do it.  T. Roosevelt

I'm sorry, I thought you wanted it done the right way.

(post #95652, reply #12 of 12)

Ed,

Seems like you and I are doing the same job. I've got the same troubles: old tiles were removed, now Im left with crusty, bumpy, unlevel cement slab to work with. fun fun. thanks for the advice about the self-levelling compound. I went to the Depot and checked it out. Seems like that stuff will work just fine for me.

Meegan