Mould has started growing on the inside of exterior walls. Its in all three bedrooms upstairs. It is growing from the skirting boards up in the corners of the room and from the roof down again in the corners. In one of the bedrroms it comes at the bottomw of the wall but not in the corners. I cleaned it off about 2 weeks ago and it has come back again. in 2 of the rooms the mould is like a dry powder but in one of the rooms it is more damp. we have lived in this house for 8 years and it has only started appearing the last 9 months i keep cleaning it but it keeps coming back.

Jackie Brindle, December 2009

Mould forms on surfaces where the humidity is greater than 70%rh; heating just makes the problem worse and air can hold more water the higher the temperature. Ventilation or dehumidification to keep the RH down is the only way...

Check on the article on this link http://www.askjeff.co.uk/rising_damp.html

Robin Farley, December 2009

You need to ventilate more or increase the warmth in the rooms. Check the damp area outside and see if a rainwater pipe is leaking.
Wipe off the mould growth with a weak solution of household bleach in water. Clean off with warm water. Allow to dry off and apply coat of antifungal wash. Prior to decorating apply a coat of stain block.

BarryF, December 2009

When warm air meets a cold surface water in the warm arir condenses out on the cold surface - microscopic fungi grow.

keep the steam down & ventilate more & wipe up the damp when you can

This link might be useful to you...

http://www.scotland.gov.uk/Publications/2005/05/10103020/30217

Good luck...

Peccavi, December 2009