John wrote:
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

It's certainly a problem on SW facing walls in this area, but IME the
clear seals aren't very effective.
Are the bricks rendered/painted?