The type of finish on a wood floor dictates what proper maintenance steps should be followed. A homeowner should review the original floor installer’s or refinisher’s records, which should note the finish manufacturer and type of finish, applied to the wood floor. The finish manufacturer’s suggested maintenance procedures should always be followed.

If such data is not available, you need to determine if the finish is a wax finish, shellac or varnish finish or a surface finish. If the floor was installed, or last serviced, before the mid ’60s, you should assume the finish used was varnish or shellac. To determine this, scratch the surface with a coin or other sharp object in a corner or other inconspicuous space. If the finish flakes, it is probably shellac or varnish. Shellac and varnish are rarely used anymore and require full sanding to remove before application of a surface finish or wax finish.

Next, check the floor for wax finish. In an inconspicuous area, corner or behind a door, apply two (2) drops of water. If, within ten minutes, white spots appear under the drops of water, the floor has a wax finish. To remove the white spots, gently rub the spots with #000 steel wool dampened with wax.

If the finish does not flake from scratching with a coin and white spots do not appear from the drops of water, the floor has a surface finish and should be maintained accordingly.

Source: NWFA