We had a problem with our gutters, which we discovered after a very heavy rain shower caused water to come through the wall in the spare room. The gutter problem has been fixed, we think, although it hasn't rained yet to be absolutely sure! We've been running a dehumidifier in the room overnight to try to get it to dry out, but there is the beginnings of mould 
. Obviously we're going to need to have that wall replastered/papered/painted again.
Can anyone recommend what workmen we need to start with? Also can I just clean the mould off with bleach to try and stop it spreading? Should we wait til we know the water ingress is definitely fixed, or are lead in times for this kind of work long enough that we'll know for sure anyway? (We're in South London if that makes a difference) Claim on home insurance now, or get some quotes first?