I wrote a while ago about problems with damp coming into the house where the new extension is. I've had a good look and can't see anything wrong so I got a builder in. I thought he's going to be expensive but he said it's basically down to porous bricks. The wall is battered by the prevailing south-westerly and the rain just soaks through. Not much but a little. He's seen it in lots of houses round here. Is this likely? Can I really just fix the problem by painting that weatherseal stuff on the wall?
Thanks