We have an extension room with a cavity wall and the inside wall is very cold. I drilled a 5" hole in the inside wall just at the concrete floor line. Inside the cavity is very cold and there is a draught. The cavity extends to about 6" lower than the internal floor. It is damp, if not wet, down in the cavity. So, there must be a way for air to get in. We replaced the ceiling in this room and the top of the cavity is sealed so, the air must be coming in from outside.
Can't see anywhere outside where air can get in.
Any ideas?
Can't see anywhere outside where air can get in.
Any ideas?