No cavity barrier at top of timber frame

[delurk79]

Hi,
I live in a timber frame house, it's approx 13 years old. In general it is warm but over the years I've noticed some draughts at times, in places such as when I have changed a socket on an external wall or from the sides of the (unused) gas fire. I can hold a feather near the sides of the gas fire to show the draught. The plasterboard on the external walls is backed with kingspan.

So clearly the air is getting into the gap between the external blockwork and the back of the kingspan. I've tried a few things over the years like fixing any vents (in some cases the ducting wasn't long enough and left a gap) but the draught remains.

Recently had some work done on attic and I noticed that in the eaves I can see a gap between the wall plate and the plasterboard (photo attached). Should this gap be here (I don't think so, after some googling) - and if not what could I block it with as a DIY job? It's not easy to access from my attic flooring due to the slope of the roof. I was thinking of stuffing some of the attic insulation into the top of the gap (while being careful that the airflow from the soffits into the attic remains). I could just about manage that in terms of reach with a piece of timber.

Is that safe and sufficient? I mean ideally maybe the bottom slates could be removed and some kind of standard barrier could be put in but I'm looking at a DIY option that is safe and will help.

Thanks

 

[^woody^]

Timber frame cavities are normally vented to allow moisture to evaporate away

 

[denso13]

The cavities in timber frame homes are ventilated by perpend vents and can be draughty.

The insulation should go over the wall plate in your photos but it isn't a big failure. It isn't connected to the draughts you are experiencing.

 

[delurk79]

Thanks - so the idea is that air can/should get into that cavity but any hole put into the internal envelope (kingspan backed plasterboard) should not if possible allow that air inside? So the failure would be anywhere that air gets in (badly installed things such as plasterboard not going all the way to floor, badly fitted switches sockets, fireplace etc) rather than the gap at the top?

 

[delurk79]

The cavities in timber frame homes are ventilated by perpend vents and can be draughty.

The insulation should go over the wall plate in your photos but it isn't a big failure. It isn't connected to the draughts you are experiencing.

The house is plastered (plaster covers blocks, no bricks). Do perpend vents still apply then? I don't see any. Thanks

 

[denso13]

Do perpend vents still apply then?

Yes, it is required by the timber frame, not what the external wall is finished with.