I'm wanting to install multi-color Slate in my basement and I'm not sure what adhesive or thinset to use. The floor are concrete of course. Also, do I need to seal it before I grout it so that the grout cleans up better?
One more thing. Do I have to anchor the piece that goes down between the tile and the carpet in the next room?

All your question can be answered by the person who sold you the slate:rolleyes:

Any gray modified thinset will work if the slate is all relatively uniform in thickness. For slate with lots of thickness variation, use a medium bed mortar so you can make the needed adjustments in the thickness of the thinset below without the slate slumping as you move along. HD-versabond gray for a regular gray modified thinset or marble-granite mortar for a medium bed. At Lowe's, mutlipurpose for a regular modified gray or big tile and stone for a medium bed. Laticrete at Lowe's is named differently than laticrete products at tile places and some might still have stock with tile store packaging, so in that case, it would be laticrete 253 for multipurpose and 221 for big tile and stone.

Those are bagged thinset you mix with water. You do not want to use mastic (or premixed "thinset") for setting stone.

Sealing is a good idea prior to grouting but try to concentrate on just filling the grout lines and keep an old tooth brush with you and a bucket of water. Don't let grout set up before the initial cleaning in the clefts of the stone. A wet toothbrush will keep those clean as you work. Slate will drink up 2 or 3 coats of sealer without any problem.

All depends. What are you using between the 2 floors?


Umm, yeah? What ifthey bought it at a big box?

Bljack, thanks for all the good info. Well, the guy at the flooring place called it Schluter or something. It's like aluminum and is about 1 1/2" wide with an edge that the tile goes up against. I've been told that you just lay it down into the mortar and tile over it.

Pretty much. Snap a line where you want the front edge to be, Comb your mortar up to that line and set the Schluter edge. Press it into place with a margin trowel to get it fully embedded and flat. There's a tiny stand-off which is where your tile ends to allow about a 1/16" grout joint at the edge. Pay attention to that when sizing your tile for cuts if needed.

Hey Bljack, you seem quite knowledgeable about your stone, can you answer one for me? I have some quartzite stone that I got a long time ago and have been waiting to install. We are finally ready but I am a little nervous about picking the right thinset. The stone is porous like slate I assume, and has some height variation, but nothing that exceeds 1\8th inch, for a total height of about 3/4 inch. We are installing it onto a concrete surface, indoors, but will get some wear and tear as it is in the room with our wood stove. Can you recommend the kind of thinset I should use and whether to use grout for the gaps between the stones? Thanks for any help.