Cleaning Deeply Embedded Gylcerol Spill from Concrete Floor

by MEL
(NJ)

Q. There was a discharge of glycerol / glycol from a wet sprinkler system onto my unsealed cement basement floor.
Unfortunately, due to insurance red-tape, the stain was not treated for 10 week and had completely absorbed into the concrete. A Professional restoration company came in and did a cleaning process but the concrete was permanently stained. It was suggested that the concrete be painted with an epoxy floor paint to cover the staining. In preparation for the painting the floors were steam cleaned to remove any debris from sheetrock and spackling of the room. Upon completion of the steam cleaning the stain appeared to be darker and almost back to the pre-cleaning state, although not as oily. I was advised by a floor paint factory rep to conduct tests prior to painting to assure adhesion. I placed water on the stained areas and after 3 hours it was still laying on the surface, this morning after 10 hours it had absorbed but was still wet to the touch. The painter feels this indicates that glycerol is still present in the concrete and therefore will not proceed with the painting process. So my question is - What can you do to remove glycerol, a petroleum based product, that is deeply embedded within the concrete?

A. Lubricating oils or other petroleum based products may penetrate concrete. It should be mopped up immediately, covering the spot with a dry powdered material such as portland cement, fuller’s earth, or hydrated lime. If treated promptly, no staining will occur. If the oil remains for some time, other methods may be required.

Make a paste of a solution of 1 pound trisodium phosphate to 1 gallon of water and sufficient fuller's earth to thicken. Spread this paste in a layer about 1/2-inch thick over the surface to be cleaned and let it dry (approximately 24 hours). Remove the paste and wash surface with clear water.

An alternate treatment consists of the application of a poultice made by adding powdered talc or fuller's earth to a 5 percent solution of caustic soda.

These applications may need to be done more than once to completely remove the entire stain.

Because concrete is so porous, removing 100% of the stain may not be achieved.