"Dwayne" wrote in message
...
Try a toilet bowl cleaner or shower cleaner that contains acid. Put it on
the concrete for varying lengths of time and check its progress. If it is
a
fungus, acid will usually get it out. Be sure and rinse it all off when
you
are finished. Good luck. Dwayne


"Cicero" wrote in message
...

"ben" wrote in message
...
A load of black circles about the size of a penny have appeared all
over
my concrete garden path, obviously some kind of mould or fungus or
something. NOTHING seems to be able to get rid of them. Ordinary
potassium hydroxide patio cleaner, applied with a good stiff brush,
has
no effect. Bleach, even applied neat with a stiff brush, has no
effect.
I now have a path that looks cleaner than it did when it was new, but
the black spots are still there. Anyone able to suggest anything?

Incidentally, I've been looking around the neighbourhood and nobody
else
has these, in fact I've never seen them before anywhere. Everyone
else's
concrete paths have, to varying degrees, a uniform layer of black
grime
that doesn't look too bad because its even, whereas the contrast I
have
between clean concrete and black circles is rather unsightly.

Any suggestions?

==============
If you don't mind a rather wayout suggestion try wallpaper paste if you
have any left over from your last decorating job. Modern pastes usually
contain a fungicide and it might just give you some indication of what
you're dealing with. I've no idea if it will work but it's worth a try.
Alternatively look in your local Garden Centre for a proprietary garden
fungicide.

Cic.



I managed to remove mould spot on paving with steam. I used a wallpaper
remover to steam the slabs, The flat plate of the steamer was ideal, if a
little boring but the mould eventually lightened in colour and lost its grip
on the paving. A quick blast from a pressure washer then removed the mould.
I expect it will return after a while, but I'll be waiting..... with the
steamer.

Smudge