I have a bedroom wall with crackling paint. This an interior wall that is perpendicular to an outside wall. The enire wall of paint is crackling. When I put my hand to the corner of the wall which is at the apex of the outside & interior wall, it is cold. As I move my hand away from the exterior wall along the interior wall, it is normal temp and then cold and then continues to be a normal temp. My roof was just reshingled. What is causing this problem????