Hi, and thanks for a good question. I used to prep concrete for
painting sometimes, and thought Id have a head start on your problem.
First, concretes main problem is that it is porous, and so grease
(and other liquids) absorb deeply. Any solution to fix the problem
will need time to also absorb into the pores.
Second, grease cannot really be neutralized out of existence. It has
to be removed. And the standard way to do this is to use a soap, which
has a molecule that attaches to greases on one end and to water on the
other, so that the water grabs the soap, which is attached to the
grease, and washes it away. As you might guess, it is imperfect, but
gets better through time, and through repeated use.
The other method for getting grease out is to dissolve it in solvent,
or degreaser which is often a highly alkaline product, and the first
article below mentions one brand that might be worth the effort to
find called Supreme 88. But any degreaser might be equal to that one,
and again, the trick is to work it into the pores.
Note that both of these solutions might be imperfect. You may have
residues, such as powdery charcoal aspects that will lodge rather
permanently into the pores, and they are nearly impervious to chemical
attack. They might, though, wash out physically with some spraying and
There is some (small) danger of causing harm to other materials
nearby, or to yourself, so please use your own good judgement along
those lines. Im not able to offer more than information based on my
own experience, and what Ive found on the web, and there are
precautions that you should take into your own hands! You probably
know this well. One site that is very helpful is a US Gov source worth
Now, some advice from web sites that pertain:
In an article on the Fixit site called
Fixit: Removing grease stains from concrete by Karen Youso, Fixit
Editor she says specifically to use a strong powder laundry detergent
mixed with just enough water to form a paste, and to LEAVE IT ON for
A Canadian site offers some more serious solvent options here (and
note that they form a paste with these organics, and you need to use
these pastes with gloves and general good care!). Note also the
REPEATED application. They claim that grease doesnt penetrate the
cement, but Ive found this just isnt true. It may depend on the
grease. This is put out by the BC Ready Mixed Concrete Association,
and they ought to know.
Another heavy duty degreaser company, KO Manufacturing, has this
This Michigan State University Extention site on Home Maintenance adds
the one additional idea of using boiling water--another danger to be
careful of, but it increases the activity of the detergents used.
As a final note, you may be lucky to be getting to this right away. I
have cleaned old garage floors and even with extraordinary effort, not
every stain will come out. And I mean some serious degreasers. (I
think I bought mine from a Sherwin Williams store at the time. You
might also try Home Depot or the like, for a standard concrete
cleaner. Check the painting departments for prep chemicals. Red Devil,
Quickcrete, and others make standard products that might work just
Good luck. And please let me know if this was enough of a start for
you...and hopefully not too much. Read instructions carefully. Pay
attention to any warnings about cleaning a concrete surface that is
fully cured (you said it was newly laid).
If you need any clarification let me know. Ill do my best!