How to remove old engine oil stains from paving and concrete slab?

[wixxer]

Hi,
we just moved into a house which has got a paved under cover patio in extention of the car port. Obviously previous owners used to park their (leaking) cars everywhere on the paving and of course in the car port, which left us now with huge old oil stains all over the place. There are at least 3 stains as big as 1sqm each plus countless other smaller ones (about a size of a palm). There are also many stains from dripping bbq I suppose and all other dirt accumulated over the last two decades...

How do I get rid of it?
Is it worth trying to get some sort of degreaser and a high pressure cleaner (got a small one in my shed), or rather ask for proffesional help?

What would be the best degreaser for that sort of grime available on the market in Perth, WA?

Anyone knows pricing for proffesional driveway/patio cleaning?
Area to be cleaned is about 100sqm of paved area + 25sqm of concrete in the carport.
Thanks

[TermiMonster]

I have removed oil stains with degreaser. But not sure how it would go if they've had a long time to really soak in. But you can buy a 4lt of degreaser from any auto place (Auto Barn, repco, etc) for not too much and give it a go. If that doesn't work, then try the pro's.
cheers
TM

[Master Splinter]

A bag of lime and a few litres of kerosene. A heaping shovelfull of lime on the stain, and moisten it with the kero. Leave for a week or so, and the mix should draw out oil on the surface.

After that, clean up with caustic soda.

[wixxer]

Thanks guys, I reckon I'll try both methods.
@Master Splinter: Do you reckon I should do that on every oil spot? And where do I get rid of the mix? It's not really garden friendly stuff, is it?

[Master Splinter]

Do it on the big nasty ones; it should be wet, but not sloppy - the kero shouldn't run out of it...kind of like the sort of mix you need for a shower floor screed. As for getting rid of it...the last lot of mine went into a hole that was getting a sleeper put into it! (My garden friendliness ends at 'I haven't concreted over it, yet'.)

[wixxer]

Thanks mate :)

[chalkyt]

I've used a similar approach to the above with some success, plus liberal doses of "kitty litter" to suck up the residue. You can buy oil absorber material but it just looks like kitty litter at a flash price. Don't know if it works any better 'cause I haven't tried it! Generally once you have got rid of most of the muck, mother nature finishes it off to the point where there are only faint shadows left.

[GeoffW1]

Hi,

If you do use a water blaster after all that, it cleans off the surface grime as well, so you will need to blast a wider area, or it stands out as patches of whiter concrete. Looks good though.

Cheers

[jago]

They used to use cement dust in motorsport for spills not sure how it would go on stains.

[nobleglobal]

I've read that cat litter is effective (although not tried it myself). Leave it on the spill overnight, sweep it up and high pressure hose it off. Certainly a cheap choice.

[jonesyGT]

They used to use cement dust in motorsport for spills not sure how it would go on stains.

Yep, not sure how it goes @ removing long term stains tho
We used to put bags of it down to soak up the oil & then broom up.