I'll try to keep this review succinct—there's so much to write when it comes to Concretta!—but I'll say that this product was one of my only options when it came to doing a DIY, no-demo bathroom renovation. I wanted to cover over some pretty ugly tile in my shower and floor, but couldn't tile over it because the builder used a raised decorative border in the shower and the tub surround (which meant I didn't have a level surface to tile over), and tiling over the floor would have resulted in a height difference between that room and the primary bedroom that it leads into. After years of searching for solutions, I stumbled across various microcements/plasters online and finally settled on Concretta, which appeared, at least from the tutorials I found, to have the smoothest finish, and didn't require lots of surface preparation if it was going over tile.
I opted for Concretta in the "Natural White" colorway for my shower and tub surround and "Obsidian" for the floor. I started the project with the Natural White in the shower and tub surround. Having never worked with microcement, plaster, or any product like this before, I'll say that I was surprised at how quickly I got the knack of it—it's somewhat messy, as I was expecting from the various tutorials I watched in advance, but the finish was lovely and organic, and the product was also pretty forgiving (I smoothed out imperfections with a damp sponge when it was still in the drying stage, and then when it was finally dry, gave it a good sanding with a diamond grit sander, which made it really smooth).
The Obsidian floor, on the other hand, was a different story. I'll say that the final product is really gorgeous, but that was after a lot of trial and error: unlike the white/lighter colors, the dark colors seem to be quite temperamental: any variations in water in the mixture, sanding after it's dried, etc., seemed to mess up the entire floor, to the point that I had to re-do it multiple times in order to get the finish totally even. I used PlasterGuard sealant on the shower and again: that went on so easily and didn't seem to change the overall color. For the floor, though, I found that the Meoded sealer worked less well (it left streak marks and a white haze); what worked really well for me was an off-the-shelf sealant I ended up using instead (Old Master's in Matte).
Apart from all this, I want to give a huge shout out to the team at Marketplace Paints: I don't think I've ever received such excellent service. Both Tom and Matt were enormously helpful to me as I learned how to use this product (and then needed some extra pigment and Concretta shipped to me quickly last minute); they stayed in touch with me over text and phone, sometimes on the weekends; and at one point, Matt even texted me after work hours about the project. The staff at Meoded itself were even in touch with me to help me out—everyone involved was unbelievably kind and generous. There are a handful of places that sell Concretta in the U.S., but I really recommend Marketplace: when it comes to using a new product like this, you want to speak with folks who have expertise and experience, and these guys really know their stuff (or, in the rare occasions they don't have an answer, they really stop at nothing to get an answer for you from the manufacturer). And the icing on the cake is that they ship super fast!
The pictures in this review include a "before" so you can see what kind of tile I was covering and then the after of the finished project. Highly recommended!