I have a Victorian 1870 terrace house that for 20 plus years had a lean-to on the side return. This fell down 2 years ago and this past year I have had patches of penetrating damp in various patches all over of the now-exposed external wall. The exterior has a textured paint on and all looks sound.
One trader who came to inspect and quote says the internal wall needs stripping and tanking floor to ceiling. Another says it must be tackled from the exterior and wall covered with a sealant to stop rain penetrating. How do I know which way to go? Is it worth paying for a proper damp survey at this point? I'm reading on the internet that neither are suitable for an old house.
There is an air brick that is filled in from the inside but open to the outside and seem to be producing a large area of damp. The floor is concrete in the kitchen so can it safely be filled in?