Our house was constructed over varying years as far back as 17th century; at some stage 3 buildings were reconstructed into one. The solid walls are a mixture of stone and brick with a thickness of about 18-20 inches. A bedroom at one time had a door to outside steps, this has been blocked off (and steps removed) to about half the wall thickness. There is a former window that was also blocked off at possibly the same time on another wall, it has a shallower recess, either the infilling was thicker or a different material used (the wall on this side was built much latter as the room was originally narrower but widened at some stage..
The former door wall, an end wall to the house, is much more exposed as the “window” wall is facing an area roofed over with another building on the other side of this roof. I think due to the exposure the weather, gets condensation in the winter/cold weather . I don’t think its penetrating water, as the alcove has remained dry over the current very wet weather. The room is not in regular use and the window has a window left permanently on ventilation position.
This is the room we are going to “do up” next so I need to identify what to do in the alcoves, it would appear best to remove the existing shelves and fit insulation and plaster board over this. I am unsure if this is the best way of removing the problem or materials to do it?