House: Victorian Mid-Terrace

Was up in the loft yesterday, and the joists felt damp to the touch.
I added Vents to the soffets (front & back) soon after moving in but they dont seem to be having the desired effect.

What are my options to improve ventilation?

Someone has suggested that an air brick placed near the apex of the roof in the chimney (redundant, but vented) stack may help to provide more “through flow” and remove moisture.

what’s the roof construction, slate? Is there a breathes membrane, heavy felt or none?

Eaves ventilation only works of there is significant airflow (i.e. wind) to create enough pressure to suck air through. The air-brick suggestion sounds like a good one as this is usually more effective.

Also, what rooms are below the areas that are damp? One possibility is that you may not have vapour control plasterboard above wet rooms, which means that moisture is getting through to the roof space, and the limited ventilation may not be helping things.

You sure the joists are damp? Quite often cold feels damp, but they may not be – probably best to check with some kind of moisture sensing gauge – no idea where to get one from or what a good reading would look like, but they must exist). Ventilation is important in roof voids in older properties – you can get roof tile vents for this, but it sounds to me like some proper advice is required, as doing the wrong thing could make any problem worse, and it’s hard to know what is good sound advice without someone actually seeing it.

Another option is to replace a few of the roof tiles with tile vents – all the major tile suppliers do them. Some of them aren’t the prettiest things, but they should provide you with enough ventilation.

Personally, I would be looking at the vented tiles option. You say the chimeny is not used … but I personally would like to keep the option of it further down the line. You just never know.

TFM – Roof is tiled (ceramic not slate) Not sure bout membrane. From the inside its lined with that hessian style plastic stuff, so cant see the “proper lining”

Mikey – Rooms below are both bedrooms

Fisha – when I say the chimney isn’t used, the fireplace has been bricked up. So theoretically possible to use again, but if you saw the house, you’d realise it’s unlikely. Good point though.