Can anyone help please with a problem that even my roofer is stumped by?
My house is a 1930's detached and I had large damp patches where the wall meets the ceiling (and on the ceiling) on the two upstairs bedroom outer walls.
Both patches are where chimneys are with the chimney breasts on the outside. In the front bedroom I had the chimney lowered to roof level and tiled over and then an air brick near the middle and top of the chimney breast. This did the trick.
However in the back bedroom, I left the problem until it was really bad as it was inside some wardrobes. When I eventually tackled this one, I employed a different roofer to do the same things to the chimney except he felted under the tiles even though the rest of the roof is unfelted. I also had the old wardrobes ripped out and the whole wall re plaster-boarded and the worst bit of the ceiling hacked off and a rectangle of plaster board attached to the ceiling lathes and then re-plastered.
Then the damp re-appeared. When it rained I noticed damp all around the edges of the rectangle of the plaster boarded bit on the ceiling with a noticeably worse bit where the ceiling meets the wall on one side. I called the roofer who put some water seal on the bricks outside. He checked for missing pointing and for any problems with guttering and said they are fine.
This still didn't stop the damp so he put a tile vent either side of where the chimney is. The damp on the side between the ceiling and the wall now looks worse. He has now suggested that I put extra insulation in the loft over this area.
Does this sound reasonable or can anyone suggest what they think might be happening please? [/url]