Removing White Powdery Substance From Cinder Block

Lawrence Coppar

I had water seeping into a garage that has a cinder block wall. The leak was due to a clogged gutter drain that was allowing rainwater to flow at the block wall on the outside. Over time the water seeped through.

The seepage left a powdery white residue on the cinder block. How can I best remove the residue? Thanks.

TRUEPRO

This residue is from a build up of a particular element (cant recall at the time). This substance was absorbed from minerals in the water and is entirely consumed the pores of the block. You could possibly try CLR cleaner (As seen on TV) This might work. Havnt tried it before but i have tried everything else to remove the white substance from brick and block with no luck. Second option... Paint. Good luck

joecaption

http://www.masonryworktools.com/brickefflorescence.html

Lawrence Coppar

Thanks for the ideas. I'll be trying them.

creeper

efflorescence can be scraped off with a wire brush. Then wash the area with white vinegar

concretemasonry

Trupro -

The element you cannot remember is basically is calcium salt calcium that is in all concrete. If there is excess moisture, it can be carried to the surface and deposited when the moisture evaporates. Since the block are probably not "cinder block" (very rare for the last 40 years) real cinder block could also contain many different salts since they were made from waste materials that are not economical now due to the availability of higher quality aggregates.

It is an alkali and can be neutralized by an acidic product (like vinegar) after the excess is brushed off. The good thing is that it lets you know where the excess moisture is coming out.

Dick