Black mould on internal walls

[Spaniel]

Hello,
I hope someone can help me, I live in an old mid terraced house. I seem to be suffering black mould in all the upstairs rooms! I have used bleach, mould sprays and redecorating, but still it comes back! The loft is boarded out and we have central heating. How can I stop it and what paint do I use when trying to cover the stains?
Many thanks

[welsh brickie]

you need to ventilate the rooms, you can install trickle vents in the windows or airvents in the walls the mould will re occur if you dont