Damp attic since insulation

bstop: that statement puzzles me, how can the attic be colder than the outside air?
 
If there is a rapid rise in outside air temperature due to changing weather conditions, the temperature of the attic structures will be colder than the outside air for a considerable warm up time period. These rapid rises and falls in outside temperature are regular in Ireland and often quite dramatic. Last Christmas the outside temperature changed from -15 to +10 Degrees over a period of hours into Stephens Day.
 
That's a pretty rare occurrence though, all the same.
 
Rapid temperature changes are a common occurrence in Ireland's changeable climate. The change at Christmas 2010 is an extreme example.
 
Rapid temperature changes are a common occurrence in Ireland's changeable climate. The change at Christmas 2010 is an extreme example.
Rapid changes are relatively common but the temperature differential involved is rare.

The most common occurrence of condensation in an attic after installation of insulation, by far, is the ventilation being blocked off by the insulation or that it was an older house with a weak airflow into the attic but one just about strong enough to ventilate before the extra insulation was put in.
 
That is exactly what happened to my house, the insulation was blocking the vents, plus the shower extractor was not ducted to the outside, but I recall the severe low temperature was for a couple of weeks and my attic was dripping. I will add that there must be no entry for the warm air from the house to the attic, this carries moisture.
 
 
With warm air on the outside, surely the condensation will be on the outside not the inside. Its the warm air that carries the moisture
 
 
With warm air on the outside, surely the condensation will be on the outside not the inside. Its the warm air that carries the moisture


The warm outside air enters the attic if it is well ventilated and wets the inside as I have previously explained.
 
 
bstop:
I disagree. If you heat up cold air it will go dryer and can absorb more moisture, so it will be dryer inside, it’s measured as Relative Humidity.
When I was living abroad in a hot country, I had my air condition on inside the house and the windows used to condense on the ouside.