The attic is damp

[Andsoforth]

In the last year we changed our windows and doors. It’s made a massive difference in the house - warmer for longer and our usage of gas has dropped (that’s not stopped the bills shooting up of course)

But now the attic is damp which it never was before. I’ve always stored the Christmas decorations in cardboard boxes and they are all a bit damp, some nearly falling apart. I noticed that some of the roof joists are damp too.

We have fibre glass insulation on the attic floor. What else should we be doing up there?

Is there a shower/bathroom extraction fan, and if so does the vent pipe pass through to outside or just stop in the roof void?

You need flowing air in the attic. Check if your eaves vents are blocked. If your joists are damp they could go mouldy and then you've got problems.
If you have free flowing air in the attic (but the insulation prevents that causing heat loss to the rest of the house) or shouldn't be damp like that unless you have a source of moisture supply like pp said, bathroom vent extracting to the attic, or leaking chimney etc

We have the same issue. I don't think there is enough air flow because it's not breezy like our new build roof space was. Looking to fit vented soffits. Our mates had the same problem and they have drilled holes either end of the roof space to get air flowing. Our house is also high humidity and we're getting extractor fans for kitchen and bathrooms that vent outside.

The damp could be from three sources that I can think of.

Roof problems. Have you checked that you don't have any cracked or broken tiles? Is the flashing around the chimneys in good condition?

Condensation. Have you checked there is air flow in your loft? Drilled fascias? Insulation shouldn't go all the way to the exterior brickwork?

A leak from pipework/cold water tank. You'd normally see this as damp patches on ceilings but might be a very slow leak.

We had a similar problem after we boarded our loft. It was an awful amount of condensation. We bought felt lap vents which are easy to install and the problem has gone away.

Good question but no.

The eaves/soffits were replaced 2 years ago, and have vents every few feet so there should be good air flow. Worth a closer look. Thanks

I wonder if the kitchen or utility extractor fan is venting too close to a soffit vent - another thing to check in daylight. Thanks

I’m fairly confident that it isn’t a leak as I’d expect the problem to be concentrated in one spot, and it’s spread evenly along one side.

I had this. Warm air from the house would hit the cold felt and condense and it would drip onto the boards etc. The problem gets worse in especially cold weather for obvious reasons Felt lap vents mostly solved the issue albeit it still happened a bit the last week or two when we had sub zero temperatures for days on end.

Completely gone now that the temperature is above freezing, but could look into vent tiles in the future

Hi, how many felt lap tiles did you fit? Thanks

For us it was the tube from the extractor fan from the bathroom, had a split in it. We also put in vents in the roof, which helped the condensation.

Mines dripping with condensation at the moment , that's only on the side where the sun doesn't hit the roof though . The other side is fine .

All down to lack of air flow i'm told , got 12" thick insulation in the loft and that causes the loft space to become cold which in turn leads to any moisture in the air condensing into water . My eaves are blocked up with wire wool to prevent the mices getting in though , fitting some soffit vents next week and pulling the insulation back from the eaves which hopefully will give me some ventilation

Sorry to hear how many more of us there are with this problem

My mate has been quoted £1600 to fit 24 vented roof tiles to cure this problem.

We had this the past few weeks and the amount of condensation and pooling water was awful. I must admit I had a massive worry about it as it's a recent house purchase. We fitted some vents purchased from amazon into the felt and the problem has been resolved. Cost less than £30.

I think we have had an issue. Never noticed before but we got the Xmas decs down and noticed a couple of the bags were wet on the bottom. Trying to ventilate and keep an eye on it. Think it might be because it was minus temps and then thawed out

We fitted 20 as we have quite a large space but I think 10 would of been ok.

By adding the insulation to keep the house warmer the heat loss to the attic is less so the cooler air is causing any moisture to condense on the colder surfaces.
Check that the insulation is not blocking the eaves vents at the junction of the roof and the wall. You need airflow in the attic space. If there is no obvious blockage then you will need to improve ventilation by some adding venting tiles to the roof.