If you pressure washed it and it is still dark pour laundry bleach on an
area, if it lightens in a few minutes its mold. If its mold use a garden
sprayer with 50% bleach, or mop it on let it sit for hours, then
powerwash again, if its mold do your basement walls also . You may have
a high water table keeping the floor damp, a dehumidifier would be best,
if its mold.
When you pressure-washed it, did you use plain water, or did you use a
The dirt you see could be fine clay. It's difficult to remove with
Try mopping with a solution of TSP (the real stuff, not the substitute)
and brushing the solution with a broom, then rinsing.
By the way, when you pressure-washed, where did all the dirty water go?
Into your sump pit? Does that drain into your septic tank?
I figured a picture would be much easier than trying to explain it.
It's not mold, it's just where there was about 2 inches of red clay mud
in the basement and all the builder did was sweet it out....so
basically...there was about 2 inches of red clay mud still in my
basement when I moved it. I pressure washed it, adding a detergent
first. It worked wonders, however, I do not feel its clean enough to
seal. There are still some splotchy areas of clay that seems to be
embedded in the concrete? The first two pictures are of the pressure
washed area - and the third picture is of an area that hasn't been
pressure washed yet.
Oh yeah, and when I pressure washed the first time, I just squeegied
the water out into the driveway/yard.
Ether Jones wrote:
On 29 Jun 2006 20:33:30 -0700, with neither quill nor qualm,
firstname.lastname@example.org quickly quoth:
Those could be some clay stains in the concrete. I'd give it a few
more pressure washings (without detergent) to see if any more would
come out and to remove all traces of detergent before sealing if it
Also, you might try some lacquer thinner, naphtha, or mineral spirits
on a red spot to see if any more color comes off on a cloth before
doing that. Maybe a quick solvent wash is in order, then let it dry,
and then pressure-wash it squeaky-clean.
It may seem like a lot of extra work, but prep work is the foundation
of all tasks. The better you prep, the better the final work will be.
A solution of muratic acid and water..mop on...wait about 20 minutes and
rinse...it gets everything.But do not leave it on too long as it will start
to eat the concrete.
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