Urethane or polyurethane is a liquid plastic that comes in a gloss or satin
finish. This coating is durable, and with proper care you should not have any
major problems.
To maintain the floor, sweep and dust mop as needed. Vacuum with an electric
broom or vacuum (make sure the bottom of the vacuum does not contain anything
that would tend to scratch the flooring).
Do not use a wet mop, even if your flooring has a urethane coating. Wipe with
a damp cloth that is almost dry after the excess water has been wrung out. Buff
immediately with a dry, soft, clean cloth.
Soap is rarely recommended, and for periodic cleaning of accumulated grime
and dirt it is probably best to stay with the manufacturer's recommended
cleaning product. The expense can outweigh the damage you might do to the finish
using non-recommended products.
If you want to persist in finding an alternative, in general a very mild,
biodegradable type of soap can be used on most urethane finishes - but only if
care is taken during the cleaning process.
Apply with a damp cloth that has excess moisture wrung out, and wipe clean
with a similarly prepared damp cloth that does not contain any soap. Follow this
by wiping dry and buffing with a soft, clean cloth.
Prevent denting and scratching of your flooring by outfitting table and chair
legs with rubber tips or plastic-coatings. Watch out for high-heel shoes, which
can easily leave dents in your flooring. These dent marks are permanent and can
be removed only by re-sanding.
It is important that you never apply a wax floor dressing to a urethane
finish. The wax becomes a contaminant to the urethane and the urethane peels
off. New urethane coatings cannot be successfully reapplied.