If the wall affected by damp is not of great extent, the most effectual remedy is to cut out the old brickwork in small portions at a time, and rebuild the wall with Staffordshire blue bricks set in cement; or ordinary stock bricks may be used, with a cavity between the inner and outer skins. If the wall is only 9iu. thick, this would necessitate either thickening the wall or making the inner skin of brick on edge. If it is not desirable to pull down and rebuild, line the inside of the wall with thin lead paper, Willesden paper, or Callender's sheet bitumen.