Oil & Grease Stain Removal
Oil goes into concrete, not onto it. That single fact explains why the pressure washer did not work and what does.
Concrete Is Porous, and Oil Takes Advantage of It
Bare concrete is not a sealed surface. It is a network of fine capillaries, and oil is thin enough to travel down into them. Once it has, the stain you can see is the top of something with depth, and nothing applied to the surface at high velocity is going to reach the rest of it.
That is the whole reason this needs a different approach from general cleaning. A degreaser has to be worked into the surface and given time to break the oil down and draw it back up, which is slow, sometimes needs repeating, and looks like nothing is happening while it works.
Time matters more than anything else here. A fresh drip dealt with in the first week usually comes out completely. The same drip left for three winters has migrated, and the honest outcome is a large improvement rather than a blank slab. We would rather tell you that at the quote than surprise you with it on the day.
Motor oil on a driveway and cooking grease outside a restaurant back door are the same chemistry and the same fix. Sealing under concrete wash and seal is the part that stops it recurring.
How We Remove It
Degreasing is a chemical process on a clock. Rushing any part of it is what produces the lightened-but-still-there result people get from a rental machine.
Assess Age, Depth and Surface
Fresh or old, sealed or bare, concrete or pavers. This decides both the product and what we tell you to expect, which we would rather do before the work than after.
Apply Degreaser and Agitate
A degreaser is applied directly to the stain and worked into the surface so it reaches into the pore structure rather than sitting on top of it.
Let It Draw
The product needs time to break the oil down and lift it back toward the surface. On older stains this step gets repeated rather than compensated for with pressure.
Clean the Whole Surface
The slab is cleaned edge to edge with a surface cleaner, not just the treated patch, so you are not left with a bright spot in the middle of a weathered driveway.
Seal, If It Makes Sense
Sealing keeps the next spill on the surface instead of in the slab. We will tell you honestly whether the weather window is still open for it this season.
Where We Find It
Oil and grease staining turns up in a short list of predictable places.
Driveways & Parking Pads
Drip patterns under where a vehicle habitually sits, usually two or three distinct spots rather than one.
Garage Aprons & Floors
The transition slab at the garage door, which takes both drips and whatever gets tracked out on tyres.
Restaurant Back Doors & Dumpster Pads
Cooking grease rather than motor oil, and the surface most likely to be looked at during an inspection.
Commercial Lots & Loading Areas
Delivery bays, fleet parking and anywhere vehicles idle, where the staining is spread thin over a large area.
Paver Driveways
Harder than poured concrete, because oil gets into the joints as well as the paver faces and the joint sand often has to be replaced.
Frequently Asked Questions
Can an old oil stain actually be removed, or only lightened?
It depends almost entirely on how long it has been there and whether the slab was sealed. Oil on sealed concrete usually sits on top and comes up well. Oil that has soaked into bare, porous concrete over several years has migrated down into the slab, and what comes out is what can be drawn back to the surface. We are straight about this at the quote rather than after: on an old, deep stain the honest expectation is major improvement rather than disappearance.
Does pressure washing remove oil?
Not on its own, and this is the most common disappointment people have after renting a machine. Pressure moves what is on the surface. Oil that has penetrated has to be lifted chemically with a degreaser that is given time to work, and often more than one application. Pressure alone mostly just cleans the concrete around the stain so the stain looks worse by contrast.
Will removing the stain leave a clean patch that stands out?
It can, and it is worth knowing before you start. If a driveway has years of general soiling and you treat one stain aggressively, you get a bright spot. That is why we clean the whole slab rather than spot-treating, so the result is uniform. It is also a good argument for doing it at the same time as a general driveway clean.
How do I stop it happening again?
Sealing is the real answer. A sealed slab keeps oil on the surface where it can be wiped or washed off, instead of letting it soak into a porous material. That is the main practical case for concrete sealing on a driveway, more so than appearance, and it is why we usually suggest cleaning and sealing together rather than cleaning alone.
Have a question we didn't answer? Call (425) 298-7041or submit a quote request — we respond within 24 hours.
Driveway Cleaning Across Seattle & the Eastside
What causes the staining shifts with the kind of property. Older Seattle, Renton and Snohomish driveways are typically decades-old bare concrete with years of accumulated drips and an open, thirsty surface. Newer Issaquah, Mill Creek and Newcastle pours are tighter and more likely to have been sealed at some point, which usually means a better outcome. Commercial and multifamily sites in Lynnwood, Everett and Bellevue bring spread-thin fleet and delivery staining rather than a few concentrated spots.
Choose your city for how we handle it locally and what to expect.
Don't see your city? We work across the greater Seattle area, roughly an hour out from Kenmore. See the full service area, or call (425) 298-7041 and we'll tell you straight away whether you're in range.
Related Services
Oil removal is nearly always done as part of one of these:
Send Us a Photo of the Stain
Tell us roughly how long it has been there and we will tell you honestly what is achievable before you spend anything. Free quotes across Seattle, Bellevue, Kirkland, Redmond, Sammamish, Bothell, Kenmore, Woodinville and the wider Eastside.
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