limestone leaching up from concrete under paver

[Johnny B]

About the only section on the forum to ask:

Apparently there is “limestone” (what I was told) leaching up from concrete (or something) under brick pavers into a door’s metal threshold area; the metal threshold butts up against these outside brick pavers. Is there a decent (safe, cheap, etc) chemical to eat it away/ clean it nicely. Carbonic acid? Vinegar/ acetic acid/ HCl/ muriatic acid. Almost every type of acid dissolves limestone, what would you suggest?

http://glenwoodcaverns.com/pdfs/Dissolv ... h-Acid.pdf

And if I don't see an immediate reaction then ok to letit dwell a while I assume.

I understand it takes water pooling in the area to create this “leaching limestone” problem So solving that drainage issue is a priority.

Thanks

 

[Johnny B]

ChemGeek was kind enough to send me the below:
This sounds like it could be efflorescence....
http://en.wikipedia.org/wiki/Efflorescence

Though acid may clean it, you might have to have some sort of seal to prevent more water from migrating from under the concrete.

You should also post this question on the forum since others are better experts at this than I am.

 

[solarboy]

This is usually caused by salts below leaching up. It is usually excluded from guarantees. The usual advice is just to wait for it to go away.