Acid Stained Floors

Acid stained concrete floors are a good alternative to other flooring options and often more cost effective. The coloring process uses an acidic solution that contains metallic salts. These salts are deposited on the surface when the “free lime” present is etched. This coloring process exudes warm variations or “mottling”. This can be intensified through multiple applications and different dilutions.

Every concrete floor is unique and it is unknown as to the intensity the stain will take on an individual slab. Successful applications come from applicator experience.  Test areas under cabinetry or utility areas are used to show coloring samples to clients.

If you are planning on an acid stained floor prior to even having the concrete placed is the best scenario.   The mix design may even play a part in the outcome of an acid stained floor. Fly ash should be avoided in the mix as it does not take a stain. Curing compounds also may affect the staining process.

Concrete that is placed, with acid staining in mind, should always be treated as a finished floor. All tradesmen should be advised to protect the concrete at all times, because it is a finished floor. Adhesives and plumbers glue dropped on the surface are examples of blemishes that usually become permanent features on an acid stained floor project.

If a concrete slab has multiple blemishes, an overlay may be applied to create a “blank canvas” which can be acid stained. Acid staining an overlay usually results in more uniform coloring, because the free lime is more consistent.  With a stained overlay application, color samples can be used and more replicated.