CONCRETE SLAB EFFLORESCENCE
CONCRETE SLAB EFFLORESCENCE
(OP)
Hi,
I have two occurences where some efflorescence was found on a basement slab on grade. Each time, the efflorescence was located along the residual glue joints of an old vinyle flooring installed directly against the slab. The thing is that it seems to migrate thru the slab rapidly and it desintegrates the slab itself. Efflorescence should not be a rapid phenomenon, so I am doubtful. I also have a photo of it.
I have two occurences where some efflorescence was found on a basement slab on grade. Each time, the efflorescence was located along the residual glue joints of an old vinyle flooring installed directly against the slab. The thing is that it seems to migrate thru the slab rapidly and it desintegrates the slab itself. Efflorescence should not be a rapid phenomenon, so I am doubtful. I also have a photo of it.

RE: CONCRETE SLAB EFFLORESCENCE
RE: CONCRETE SLAB EFFLORESCENCE
RE: CONCRETE SLAB EFFLORESCENCE
I would go down there with a flat blade and scrape off the efflorescence about every 2 to 3 weeks. So I know that at least in below grade cmu (especially during the rainy season), it can reoccur on a pretty regular basis. It is usually harmless and seen more as an eyesore than anything else. It looks like the top surface of the slab is eroded, but my guess is that when the tiles popped up or were removed, it probably took the skin surface of the concrete with it.
Its not a humidity problem, humidity is generally associated with water in the air. Your problem is due to moisture in the soil.