Concrete is a temperamental substance. While strong and long lasting, it has the most stringent of requirements when preparing if for flooring, sealers, glues, overlays and coatings.
It is very common, unfortunately, in the residential world to come across ‘do it yourself’ flooring products that purport to be “easy install” with minimal prep. How often have you heard of someone saying: “I bought this great epoxy concrete floor kit from the hardware store. I installed it without issues and it looked great! However, a few months later it started to bubble and flake off.” Yes, it’s true that DIY type products are of lower quality than the systems installed by professionals however, the reason they fail is more often a result of insufficient or completely skipped surface preparation. This is the case even when installing glue-down flooring or mortar bases to prepare for tile or natural stone work.
Sanding & Washing: Common concrete surface preparation methods in the residential space are sanding or washing the floor with TSP. TSP is Trisodium phosphate available in powder form at any hardware store.“TSPs are used as cleaning agent, lubricant, food additive, stain remover and degreaser.”
Degreasing, washing and sanding might be a good way to clean a surface but it still does not suffice as a proper concrete surface preparation method for floors that are set to receive a coating or overlay. This preparation method only cleans the surface and removes some weak points that could lead to de-lamination (or flaking off).
Grinding or Shot Blasting is the method of removing a micro layer from the concrete slab. Not only does this destroy and remove any bond breakers from the slab but it also creates a profiled and porous substrate. A product applied to a sanded or washed surface must adhere to the surface for the long term in order to maintain integrity. A floor system installed over a grinded or shot blasted surface will sink into fresh concrete and expand within the pores. The end result of applying any floor system over grinded or shot blasted concrete surfaces is a floor that is literally anchored deep in place integrally rather than simply being glued to a sub par surface. This will not only lead to better adhesion and longevity of quality but also yields a stronger and more impact resistant floor.