There are a number of proprietary oil-stain removers available, but we have not yet found one that works well and removes all of the stain, although some of the commercial cleaning agents supplied by specialist construction chemical companies can remove most of the stains.

Prevention is better than cure, so put a cardboard or wooden 'drip tray' underneath any leaky engines. Note that tarmac will degrade if contaminated with oil or a thin, oil-derived product such as petrol, diesel or hydraulic/brake fluid. This damage can not be treated. You may have to repair or replace seriously affected areas.

The sooner an oil stain is treated, the more likely it is to be removed. Use a cloth to soak-up any oil droplets on the surface, but don't smear or rub the oil into the surface. Fresh oil stains can be soaked up by proprietary absorbent materials or even some of the clay-based cat litters, cornflour or talcum powder. Any residue remaining after treating with an absorbent agent can sometimes be removed or ameliorated by scrubbing with a detergent and brush before washing down with water. It may take several attempts for this to work. Clean oil will generally soak into the paving and there will be little evidence of its presence after a few weeks. Dirty oil can be very difficult, if not impossible to completely remove.

For more stubborn stains, you could use a degreasing agent or engine cleaning fluid such as Gunk, but always test a small inconspicuous area first for adverse reactions.

If the stain is proving impossible to shift, consider replacing the contaminated area of paving.

For cleaning oil from plain, trowelled concrete:

Here are some tips we've picked up from elsewhere for cleaning concrete. These methods should not be used on colored, or imprinted concrete, or on concrete pavers, or tarmac.

Mix 1 measure of trisodium phosphate with 6 measures of water. Daub this over the stain with a clean, old paintbrush and allow the goo to dry completely before scraping off the dried paste, which should, hopefully, bring most of the oil with it. Rinse the concrete surface and scrub vigorously with a stiff brush and clean water.

Prepare a solution of 5% sodium hydroxide (caustic soda - NaOH). Daub it over the oil stain using an old paintbrush and allow it to dry for at least 24 hours. Rinse and scrub with clean water, then repeat as required.

Paint white spirit or turps over the stain. Let the solvent evaporate for at least one hour before rinsing with hot, soapy water. Repeat as required.