"Bill Reynolds" wrote in message
news
I have a small patch (3"x3" ) of a black mould on a piece of drywall.

What is a good way to kill it?

TIA

use bleach. but before you do, you need to find out what's causing it
which will probably mean removing the drywall in that area anyway.
Otherwise, you're just covering up a problem that is bound to cause more
headache down the road.
Good luck,
cc