The removed wall that should have stayed
This week I was asked to assess a house with rapidly growing cracks. On the ground floor, the contractor had removed a wall A perpendicular to the rear wall and, as often happens, installed a support beam to carry the vertical load. This 1920s house, however, had a peculiarity. On the first floor there was no load-bearing wall (= external masonry in the longitudinal direction). Longitudinal stability was instead provided by a partition wall B between the bathroom and the bedroom. Wall B stood above wall A.
Once wall A had been removed, wall B could no longer transfer its horizontal load to the foundations without large deformations, so the cracks grew quickly. By installing a portal frame in the longitudinal direction, the horizontal loads can again be carried down to the foundations without large deformations.