On Feb 21, 4:32 pm, wrote:
Well, as a followup, I managed to fix the source of the water leak in
my wall (overflowing sewer pipe that wasn't capped during a botched
later-nineties remodel ).

Anyway, that leak had caused a nasty mold infestation on my drywall
and in the cabinets.

So, I figured, with the water leak closed off, and the walls and
cabinets scrubbed down and Cloroxed, and, all rotten wood or drywall
removed, then treated all of it with Concrobium, that I'd have the
mold smell licked.

And, I was largely right, until it hit sunset, and the smell came
back. As it turns out, the mold smell comes back at night, and then
every day, goes away. I'm guessing this is due to the condensation and
the night air in my extremely humid (South Louisiana) climate.
Sooo:
1. Does that seem to make sense that night air is reigniting my mold?

2. So, what do I need to do? I'll be buying a dehumidifier, but I
don't really want to run it 24/7/365. Can I install some sort of
moisture barrier between my masonry (concrete block) walls and the
drywall/wood bolted to it?

Thanks in advance,
-Matthew D. Diez

High humidity make mold active. Suppose your room humidity 50% at 80F
during the day -- mold is suppressed. The same air will be at 100% RH
if the room temperature drops to 60, making the mold active. So if
your air is not circulating, and night temperature is significantly
lower than day temperature, mold might be active.