Re-coating
Without periodic recoating, this is an example of the damage that can happen to a stained concrete floor as the sealer is worn through or delaminates.
Most acid-stained concrete floors have a floor finish (synthetic wax) over top of the concrete sealer. A certain amount of abrasion and scratching from foot traffic, children playing, pets, stationary objects and carts or dollies, over time, is unavoidable and will eventually erode the existing floor finish. The floor finish needs to be restored periodically so that the concrete sealer and stain, below, is not affected. If the floor finish is re-coated periodically, the concrete sealer, itself, should never have to be re-coated. How often to re-coat with floor finish most depends on the building environment. In homes, once per year is a good rule of thumb, whereas with businesses, it should be more often: at least once every 4 to 6 months.
A commercial grade floor finish from a janitorial supply house should always be used - not one from a hardware or grocery store. The finish is best applied sparingly, with a garden sprinkling can, and spread with a lambswool applicator, or loop end mop, in very thin, uniform coats. (Note: loop end mops used for applying finish are slightly different than those used for damp mopping: they are made of a finer fiber such as nylon filament yarn or microfiber.) A new coat of floor finish does not take long to apply and will dry in 30-45 minutes, if not applied too heavily. Also, if the acid-stained concrete floor has a saw-cut pattern, or joints, be careful not to fill them with floor finish. Floor finish goes down milky white and may collect too deep in the cuts or joints to clear up as it dries.
Stone Medic “Friction Stone”, by Ecolabs, is the best floor finish on the market today for acid-stained concrete flooring.
Floor finishes are inexpensive - usually no more than $20 per gallon from a janitorial supply house. They come in matte, satin, or high gloss, and vary in clarity and depth, as well. Stone Medic “Friction Stone”, by EcoLabs, is a great floor finish we have used in the past. It leaves a “matte” finish, that has a completely friction-free, non-slip, minimal-skid, attribute to it.
Also, "Hazing" is a common problem encountered with floor finishes. It's caused by: 1) excessive humidity during application; 2) applying additional coats before previous coats have fully dried; or 3) applying over a dirty or contaminated surface. "Powdering", or chalking, of a floor finish, a lesser problem, is caused by: 1) applying under cold conditions (below room temperature or near poorly insulated exterior walls or entrances); or 2) applying over an unsealed or excessively porous substrate. These problems can be resolved by stripping the floor finish, correcting the source of the problem, and then re-applying more finish.
Read more about Stained Concrete Floor Finishes in our next Maintenance Section, and how they differ from Stained Concrete Sealers.