proper thinset consistency

[harley]

Hi Mark,

Could you please tell me what the proper consistency of thinset for setting floor tile 12x12 is. I have mixed some but I'm not sure. I was to thick. Also what size v notched trowel do I use for the wall tiles.
Thanks,
Harley

[Mark D.]

Harley,
What kind of tiles (ceramic, granite, travertine, etc..) and what type of thinset?
Mark

[harley]

Hi Mark,

I'm using marble 12 x 12. The thinset is TEC Full Flex Latex modified thinset mortar,white.
Thanks,
Harley

[Mark D.]

Harley,
on the bag should be the proper mixture. It should be consistent and not runny. When I have worked with latex thinsets in the past they do seem "drier" than regular thinset. I would just mix it according to the instructions and apply it to the substrate with a 1/4" or a 3/8" square notched trowel, making sure to butter the edges before I laid them in to the thinset.

On the verticals you can either float a wall with a v notched trowel (something like 3/16" should suffice). The reason for the v notches on the vertical is that the thinset will stay there in place on the wall better without the large square grooves . I have also seen verticals done where they mix the thinset and make little balls out of it the size of a golf ball. They put a ball in each corner and in the center on the back of each tile and press it up to the cementboard substrate. I have seen this done with marble and travertine both, but the tiles I saw it used on where 18" & 20" square tiles respectively. The "balls" allowed more play so the installer could make sure all the tile faces were on the same plane. So you have a couple of options there. Make sure on your verticals that you don't go higher than 3 or 4 courses of tile per day as the weight could cause the bottom course to buckle and that would look bad.

Glad to be of service,
Mark

[Stone Dude]

thicker than sour cream but not as thick as peanut butter. trowel the thinset on the floor and butter the (complete) back of each piece. if you do not spread some on the back of the pieces it will not bond. i just had a travertine tile literally cave in under my floor machine for that exact reason. when i replaced the tile, i found that it had only bonded in the corners and not in the center. 9 out of 10 tiles have a hollow sound, and im expecting more problems.

[Mark D.]

Guess they tried to save money...what is latex thinset now, $20 per bag? I stand corrected.
Mark

[Stone Dude]

im level grinding 1300+ ft of travertine. some of the lippage measured almost 1/4 inch. i can tell that they had different guys laying tile, one room was decent, the rest was embarassing. ill post pics later. i got it flat. im doing 220 and 400 tomorrow, filling on monday.  i have no idea how much thinset costs. mixing thinset and grout is more important than most people realize. i would recommend a latex additive when you do the grout too. 1/2 latex 1/2 water. it will help bond a lot better and the grout will be more durable.