I cannot advise as to attachment methods recommended, perhaps contact the manufacturer's service line, but if you start screwing into concrete, make sure you don't have a post-tensioned slab or you could run into a damage situation with that. Cables are supposed to be buried at least 2 inches below the top of the slab in those situations, but if you hit even one thread, it could be an irreparable problem.

thanks for the reply SJ! I was leaning towards not using the cement board but wasn't sure if it was needed or not. we're not using a tile setter we were going g to lay it ourselves. it's a small area and I've been laying stone outside for years, just wasn't sure about this exact application. if I go without the board, should I just use some redguard on the concrete and lay the stone on that? or is there a better way to prep the slab?

It all depends on how flat your slab is and if it has a finish of any kind. And the flatness rating is what is the big issue with slabs. You might need some grinding, etc.

You don't need the cement board. Just make sure slab is flat (and hopefully level), grind and/or self-level as needed, and be sure to use a decoupling or anti-fracture membrane.

thanks SJ and Strategery, really appreciate your responses! and decoupling or anti-fracture membrane you recommend? I used redguard when I did our backsplash, would that work in this instance?

Ditra. Over a FLAT substrate.

Schluter-DITRA is the industry standard membrane. Mapei has a competing product (Mapeguard 2) which is peel-and-stick and needs primer. My house used both.

alrighty I'll look around and make a decision, thanks a lot for your help!

Notice: Flat is the minimum requirement. Do you have photos of the current surface?

sorry it's a little messy from the drywall work. but the black stuff is the adhesive that the previous owners used to glue down the linoleum. I know I'll have to clean that glue off, which will be a pain. the room is not very big at all as you can see. and the concrete slab is rather thick.

Hire a Pro. That’s gonna need hella grinding and SLC to be remotely tileable. No pro would do that and then leave the rest of the job to you. Hire the whole. https://www.ceramictilefoundation.org/homeowners-guide-to-hiring-qualified-tile-installer

okay after looking into it, the adhesive from the linoleum could potentially contain asbestos. obviously I wont try to remove that myself, but is it okay to cover it? would an expoxy type paint or primer be okay to use? I'm not finding much help online so I figured I'd ask you guys.

". . . Adhesive from the linoleum could potentially contain asbestos."

You just upped the budget and potentially got the government involved here. I don't even know what to say to help you other than I hope it works out. This isn't something you want to be handling on your own, I don't think, even if you're trying to cover over it. Certain regulations pertain to this situation in most jurisdictions.

I know there are ways to encapsulate the mastic...I just don't know the products. I know many of our tile setters on this forum have dealt with this situation successfully.

Epoxy paint won't grab the mastic...and then the tile won't grab the epoxy paint = total fail = bigger mess then you started with.

Encapsulation is possible. It takes a well versed tile setter/concrete specialist to know the details. It can be done. The steps you need to take are several levels more difficult than just 'scraping up' the mastic.

thanks for the responses guys. do you think covering it with some type of epoxy, and putting down the schluter ditra or something similar would be sufficient enough?

Again, the Ditra mat needs to STICK to something. Epoxy paint, etc are bond BREAKERS. Do NOT go this route. It is a MASSIVE fail. The only thing you can use is a product SPECIFICALLY designed to go OVER TOP of asbestos-filled mastic. It is a cementatious product...a very special self-leveling product that is used BEFORE you use something else to get the Ditra down.

“Could potentially contain” is not “does contain”. You need to have it tested if it’s prior to the 80’s.

Get it tested. It's not expensive. Knowledge is power and there is no need to guess. If it comes back negative then you are ready to rock! If positive, well, then at least you can form a proper plan.