Help with Mould problem

[summerman]

Have recently moved to a bungalow which is approx 12 years old and it seems now we are entering the damp climate i have the appearance of mould appearing along the top of the wall in the bedroom & bathroom.
All the windows do get condensation on them in the mornings to varying degrees but they all have ventilators fitted which are open although we have venitian blinds fitted with do cover to some extent the vents.All pipes for water and heating are under the floors so none in the loft omitting the cause to be a leaking pipe. The insualtion in the loft has been topped up and a builder did say that it could possibly be the thicker insulation wasn't allowing the soffit vents on the exterior to get enough air into the loft space but surely this would affect every room with an exterior wall which it dosn't.
As it is a bungalow the roof space due to the low pitch is hard to get to the edges of the building to get a close examination so i wondered could it be the felt letting drips of water through to the ceiling as the roof would be close to the ceiling at this point. I have tried cleaning and repainting but the mould is still coming through although i have heard of a anti mould paint from Zinsser which i am thinking of using but i would prefer to know the cause first before this.Any help would be appreciated

 

[^woody^]

You've got classic condensation, which is being caused by your use of the bungalow.

Mould at the ceiling edge is typically due to a cold spot at the eaves - no or reduced insulation in that area in the loft, or cold air coming in at the eaves.

Read the FAQ/wiki or the numerous condensation posts

Anti mould paint will just move the mould to another surface. Deal with the problem

 

[summerman]

Thanks for that
looks like a visit to the loft for me then
As the loft insulation had been topped up i will have to look to see if it they had missed a bit