Loft condensation in cold temperatures

marco_79

We have had a few sub zero days up here in Scotland lately. I was asked to retrieve the Christmas tree from loft this afternoon and noticed a fair amount of condensation on the roof of the loft. It is coated in a polyethene sheeting but there is a fair amount of water on it. It is a well ventilated space with several gaps at the bottom of the roof where you can see daylight. Nothing in the loft it wet except a couple of things that were in contact with it. We did get a lot of insulation added a couple of years ago. Is this something to be concerned about or just a result of the really cold weather we have at the moment??

[Deleted User]

Is the loft insulation blocking the ventilation? The should be some clearance near the eves to allow air to circulate.

Chanes

marco_79 wrote: »

We have had a few sub zero days up here in Scotland lately. I was asked to retrieve the Christmas tree from loft this afternoon and noticed a fair amount of condensation on the roof of the loft. It is coated in a polyethene sheeting but there is a fair amount of water on it. It is a well ventilated space with several gaps at the bottom of the roof where you can see daylight. Nothing in the loft it wet except a couple of things that were in contact with it. We did get a lot of insulation added a couple of years ago. Is this something to be concerned about or just a result of the really cold weather we have at the moment??

We had a house that did that, it was not all the time though and there was no sign of wet or damp areas. We had that house for years and years and it sold with a building survey not highlighting a problem with the roof or roof space.

marco_79

No the insulation isn't blocking the ventalation there is visible gaps all the way round the bottom where it is open to the elements. There is a natural run for the condensation to outside.

malc_b

Modern houses tend to have a ridge vent as well as an eaves vent. Warm (and wet) air rise so a ridge vent gets rid of that.

I had a problem with condensation in my loft when the insulation was increased. I reckoned that the warm wet air was rising to the ridge but the ventilation, cold air was just blowing along the top of the insulation. Hence at insulation level it was ok but I was getting condensation higher up. You can get things to open up the felt to allow more airflow. Being a cheapskate I made some polystyrene wedges from a left over sheet of polystyrene and used these to wedge the felt open. That fixed the problem for me. But I'm not sure if your roof will be boarded since you are in Scotland.