I think this is effervescent from storm water going under the concrete.
I disagree, but you’re entitled to your opinion.
what’s your opinion? I should have gave out more information. This is a slab in a mobile home park. That I live in. My vehicle does not leak. The few times it rains here in Phoenix. The slab will be dry except for those areas. The Neighbor Next Door has the same problems. I’m looking for Everyone’s opinion on this. Thanks.
My beer is effervescent. Water migration through concrete and masonry produces efflorescence. Yes. that is efflorescence.
Talk to text. Didn’t proofread it. Good enough.
I should ask, as everyone else seems to have a different opinion from mine as to what your actual question is… “What is the question you need an answer to”?.. because you didn’t actually ask one.
I agree on efflorescence. What I disagree on is the reason for the efflorescence. I would also like to see a ‘close up’ of the affected area. Looks like the concrete is pitted from here, thus my not offering an opinion as to cause. I’m not there to perform a thorough review of contributing conditions.
It could be from a wet car dripping on the concrete, soaking in, and drying. IMHO
I get that in my detached garage in the summer, under those conditions…only mine is from parking a wet trailer in there.
I never suggested which direction the water was migrating. I would want more than this picture to suggest the source.
To me, looks like there were some poorly done patches as the broom finish of the surface is not consistent. This may be a weak link that allows some moisture to perk when it rains which is leaving the efflorescence behind.