Installing a Concrete Microtopping Over a Gypsum Sub-floor

Bob Harris continues his informative demonstrations with a 3-part video series on using Duraamen products. In this video series, Harris explains one of the common questions that Duraamen gets, which is from customers who want to apply polished concrete toppings on top of gypsum based underlayment or subfloor.

Yes! You can do this. This type of flooring option is helpful in apartments and condominiums because it helps absorb sound. Harris explains that in order to be successful with this application he gypsum must have a PSI of 3500 PSI at a minimum.

Harris first sands the floor in preparation of applying two coats of Duraamen CP1000 primer. Following the primer, start with what Harris calls a “body coat” of the Skraffino Regular in gray or white. If you wish to, you would sand that coat and over that coat, you can apply Skraffino Fine.

If you desire a superfine floor, sand the Fine layer and apply a coat of Skraffino Super Fine. Based on what you are trying to achieve, you can combine the Fine and the Super Fine. You can mix color pigment into the Skraffino. Color pigment powder can also be broadcast by hand into the wet Skraffino. Dye can also be tinted once the floor is applied. This versatility is one of the reasons that people like using Skraffino and the final outcome is up to the desires of the applicator.

Part 2 begins with Bob Harris explaining how to sand and reprime the first application of Skraffino if you feel like it needs it. After mixing the Skraffino Fine, with a white base this time, he applies it again by pouring out a ribbon of material and spreading it out as needed. After the Fine application he sands the surface with a 100-grit sanding screen to prepare it for the last and final coat of CP1000 followed by the Skraffino Super Fine with ColorFast pigment for tint.

Harris demonstrates how to create a marbleized effect by broadcasting an alternate color into the wet mix of Skraffino Super Fine. Watch as Harris demonstrates both the hand-troweling and magic troweling application of the colored layer.

After that, Harris demonstrates spraying on a water-based wood-brown colored Desso dye that is then massaged in with a microfiber pad for the final color layer. It’s easy to manipulate the color by simply spraying on another layer of a darker color, as Harris demonstrates. The final result is a marbled brown with some rosy orange highlights.

Part 3 of this “How to install concrete micro-topping over gypsum sub-floor” video demonstrates the application of the top coats and sealer coats. Using Harris’s technique, with or without a second person helping, assures that you avoid getting roller lines with the Perdure AO3 water-based acrylic coat. He follows that with application of Perdure E32, a two-part water-based epoxy. After drying, he applies the Perdure U46 water-based polyurethane gloss coat. The result is a beautiful floor that could be yours!