Most facilities do not employ personnel with the knowledge necessary to properly refinish wooden gymnasium floors.

“Twenty years ago over half the coaches were trained to recoat gym floors but that is now a dying art,” says John Prater, president of Praters Inc., Chattanooga, Tenn.

Facility managers now depend on outside contractors to perform this vital function. Gym floors present a great opportunity to increase sales and gross profit margins for building service contractors willing to thoroughly educate themselves.

The most frequent function performed by contractors is recoating. Wood floor coatings are very durable but do wear with time so most institutions budget one recoating annually.

Screening the floor is the first step in the recoating process. Begin by inspecting the floor carefully and removing any gum or foreign matter. Dust mopping is then performed to remove loose dirt and debris. Treat the dust mop with a water-based treatment.

Next, clean the floor with a water-based solvent cleaner designed for this process. Most suppliers offer products especially formulated for either traditional urethanes or waterborne coatings. The goal in performing this function is to remove any film that might be on the floor, such as residue left behind from various treatments, activities or gym mats. An automatic floor scrubber equipped with a white synthetic pad may used to apply and pick up the cleaner or a flat microfiber mop is also acceptable. The floor should be  completely dry before beginning the screening process.     

Dry screening may be performed with an abrasive sanding screen attached to a traditional floor buffer; however, a sanding machine with a built-in vacuum system is preferred. Screening produces a tremendous amount of dust that must be picked up from the floor. Machines equipped with a built-in vacuum make this process much faster.

Some floor machine manufacturers promote the idea of wet screening using an automatic scrubber. This is a process that incorporates a cleaner and a special pad used with the automatic scrubber. The idea is to apply a small amount of liquid and then scrub the floor with the special pad thereby abrading the finish with the pad rather than a sanding screen.    

One machine manufacturer recommends this procedure in conjunction with its orbital scrubber. It claims that no more than 12 ounces of water are applied per minute and that the water only contacts the floor for five seconds before it is vacuumed away. A combination of special synthetic pads and traditional sanding screens are used in their procedure. Wet screening is fast and reduces dusting and clean up time.

It is important to know what type of coating is on the floor before screening. Oil-modified coatings are typically harder and require using a more aggressive screen than waterborne products. Start with a 120-grit screen on oil-modified urethanes and if that isn’t sufficient go down to a 100-grit screen. Always use the least aggressive screen that will do the job.

Waterborne coatings should be screened first with a 150-grit screen. Janitors can move down to a 120-grit screen if that is not effective. Screen a second time with a less aggressive screen to provide a smoother surface. For example, if a 100-grit screen is used initially then do the final screening with a 120-grit screen.     

The final step before recoating is “tacking” the floor to remove any dust or residue. Use a solvent-based cleaner to saturate a terry towel. Wrap the towel around a push broom and push it over the floor picking up any particulate matter. Change the towel often. Let the floor dry completely before recoating.

The recoating process may be performed with any number of tools, from a traditional lamb’s wool applicator to a weighted t-bar that incorporates a synthetic pad. Backpack applicators as well as wide area applicators may be used. Typically two or three coats of finish should be applied depending on the type of finish used.

Louie E. Davis Jr. is a jan/san industry veteran and freelance writer based in Birmingham, Ala.