A.Bill Palmer, former
editor of Concrete Construction magazine and
president of Complete Construction Consultants in
Lyons, Colo., responds: Motor oil doesn't
really damage concrete. But if the surface is
unprotected, oil can soak easily into the
concrete's pores, where it's difficult to
Paint won't protect concrete from oil, but other
products will. According to Denise Breard, a
technical representative for sealer manufacturer
Vexcon Chemicals, water-based combination stain
sealers will resist motor oil but not gasoline.
A better choice — one that's both
gasoline- and oil-resistant — is a
water-based epoxy coating. This easy-to-apply
one-part epoxy doesn't require a separate primer
and is designed for residential garages and
basements. For the greatest chemical resistance and
protection against abrasion, Breard recommends
two-part water-based epoxies.
Paint doesn't adhere well to epoxy, so if you
want color in your concrete floor, you'll need to
stain it before applying the epoxy coating. Another
option would be to use an epoxy coating with color
in it. Some great colors are available, as well as
decorative chips that can be mixed in with the
If the homeowner does get oil stains on the
concrete, they should be removed as soon as
possible. Here's how: First, soak up any excess on
the surface with paper towels; don't rub, because
that could drive the oil deeper into the concrete.
Next, cover the spot with some absorbent material,
like kitty litter. Keep fresh material on the stain
until no more oil is being soaked up. Finally, put
TSP (trisodium phosphate; available at most
hardware stores) crystals over the stain, then add
enough hot water to make a poultice and scrub that
into the stain. Once the poultice has dried, sweep
it up or rinse it off.
Depending on how deep the stain is, removing it
may require repeating this process several times.
If even that doesn't work, a solution of sodium
hydroxide and ground limestone can be effective
— but a little bit dangerous. You can also
try degreasers; there are some pretty good
citrus-based versions around.