spots on ceiling

pooper

Has anyone any advice. All 3 bedrooms (but not bathrooms) have like damp spots on the ceiling close to the window. Not directly on front of the window, but say, on the ceiling close to the outside wall. There are no damp spots on the wall and it seems to be getting worse. (The house is about 12 years old)

Do you think this could be that i need more insulation in my attic, close to the edges (above the damp patches) or do you think water is getting in from the outside, through the walls?

And, does anyone have any solutions? My hubbie is handy DIY wise but do you think i may need to call a professional and if so, who?

Thanks

BryanF

• all air has moisture in it (internally this should ideally be about 5-60%)
• heating moist air causes it to condense - this is solved by proper ventilation reducing the RH (moist air %) to suitable internal levels (below 80%)
• condensation happens on cold surfaces (where you haven't insulated properly)
• condensation will always form on the coldest surface

so

• traditionally we have not been very good at over-lapping our attic insulation with our wall insulation - this your first consideration
• following this, have you got vents in each room that are unobstructed (remember we breathe out a litre of water over night
• is there mechanical extracts in wc and kitchen working ok + is there clothes drying in these rooms?
• is the temperature staying reasonably constant in the rooms

if there are window vents or draughty windows, this may be part of the problem, as when you close the curtains the air between the window and curtain is cooler - this hits the warmer air and moisture condenses on the cold thermal bridge ceiling wall junction above..