Pressure washing can remove oil stains, but not in all situations. Most commonly, oil stains show up on concrete as motor oil or grease from a grill. These stains can be tricky if not removed within the first few weeks. To adequately remove grease or oil stains in concrete with a pressure washer, EcoWash recommends using an industrial degreaser such as Purple Power, a surface cleaner, and a pressure washer capable of over 2500psi and a 2.5gpm flow rate.
To remove the oil stains, the industrial degreaser should be liberally applied to the surface and allowed to soak in for at least 5 minutes. A hard bristled brush can be used to help the degreaser soak into the porous surface of the concrete. After this, we recommend multiple slow, circular motions of the surface cleaner over the concrete, and each pass should lighten the stain slightly. After this process is complete, the oil stain should be dramatically lightened or completely removed.
If the oil stain has been completely set and has been in place for over a month, a hot water pressure washer may be required. The hot water can help to break up the oil and remove it more easily. This process is not guaranteed to remove the oil as some concrete oil stains are going to get deep into the porous concrete and be impossible to remove entirely. Most residential pressure washing companies do not offer hot water pressure washing due to the limited applications for residential work. EcoWash, like many other companies in our industry, does not offer hot-water pressure washing as a service.
"When speaking to customers about removing oil stains in concrete, I never promise perfection. Oil may never be fully removed from concrete." - Andrew Pfaff, EcoWash CEO
If you have spilled oil-based stain on concrete, we recommend removing the stain with absorbent towels and dabbing, not smearing the stain. From there we advise soaking the area in mineral spirits to dilute the oil-based stain and then proceeding with the standard process of soaking with industrial degreasers and pressure washing it slowly. This should be done immediately after the spill to avoid permanent discoloration.
When it comes to oil stain removal in your concrete, the most important thing to do is to temper your expectations. Complete removal may not be possible in your situation and you may have to settle for it looking lighter and less noticeable with repeated washing.
One last thing to note when working with concrete is that concrete poured less than 24 months ago should never be pressure washed. This can damage the concrete and this damage is irreversible.
If you need help with oil stains on your concrete, please contact a professional. To get in touch with a local EcoWash representative for advice or a quote, request an estimate here.