You may see white, fluffy deposits inside your plaster – these are definitely ‘salts’ which the damp has washed out within your bricks and into your plaster. Black places of mould may look on within the damp parts of your wall. You need to drill holes amongst ten and 12mm https://sub-floor-dampness07395.shotblogs.com/sub-floor-moisture-things-to-know-before-you-buy-46287403