Just read the write ups on this topic for internal walls, and wanted to pick your brains on my situation.
I have a 3 Bed/Semi (built mid 80's), and the problem is on our external wall.
We noticed a while back that there is faint/shadow outlines of the internal blockwork showing through the paint/plaster above the stair-well.
Our outside wall takes a real battering from the wind & rain (very exposed), and due to the sandy mix used (some corners cut me thinks) needs re-pointing anyway. (have started but have got a long way to go)
What is worrying is that at the bottom of the stair well (near front door) there is a patch approx 1- 1.5 m^2 that was soaking wet this morning. Was only noticed because we were shifting things that were in front (scarf/hat boxes & garments on coat rack)
As I'm behind on the repointing, I was intending to remove a few bricks on the outer wall, a couple of rows above the DPC, to see if there is a build up of "muck" that may have dropped during construction, and has now gotten sodden-through, due to the state of the pointing (visible holes through to cavity).
Is it worth doing, as the internal wall is so wet, or should I wait until I've finished re-pointing. I'm concerned that I will just trap all the moisture inside by not checking the cavity, and clearing if necessary.
Also Is it worth putting an air brick top and bottom when I do the repointing, or is this excessive.
JWP
I have a 3 Bed/Semi (built mid 80's), and the problem is on our external wall.
We noticed a while back that there is faint/shadow outlines of the internal blockwork showing through the paint/plaster above the stair-well.
Our outside wall takes a real battering from the wind & rain (very exposed), and due to the sandy mix used (some corners cut me thinks) needs re-pointing anyway. (have started but have got a long way to go)
What is worrying is that at the bottom of the stair well (near front door) there is a patch approx 1- 1.5 m^2 that was soaking wet this morning. Was only noticed because we were shifting things that were in front (scarf/hat boxes & garments on coat rack)
As I'm behind on the repointing, I was intending to remove a few bricks on the outer wall, a couple of rows above the DPC, to see if there is a build up of "muck" that may have dropped during construction, and has now gotten sodden-through, due to the state of the pointing (visible holes through to cavity).
Is it worth doing, as the internal wall is so wet, or should I wait until I've finished re-pointing. I'm concerned that I will just trap all the moisture inside by not checking the cavity, and clearing if necessary.
Also Is it worth putting an air brick top and bottom when I do the repointing, or is this excessive.
JWP
as far as cold air goes. Unfortunately the 80`s was yet another boom for building and there were still labourers on the mixer "gauging" by the shovel full . Now at least the mortar is in Silos so it`s consistant - brickwork is dead neat too . keeps your eye off the flimsy plasterboard walls /small rooms and chipboard floors inside 
