How to Repair Rising Damp on Internal and External Walls?
Rising damp can affect both internal and external walls.
Watering systems, soil above the damp course, or heavy weather conditions can subject external walls to rising damp. Visible signs for external walls include fretting mortar, paint/render peeling off or salt marks on the bricks or render.
Before & After
The two main causes for rising damp on internal walls are both a breakdown of the original dampcourse plus rubble between the walls in the cavity.
Signs of rising damp for internal walls include bubbling paintwork, a damp smell or a watermark.
The remedy for both, is to remove the render or plaster, leaving the bricks exposed, cut out the lowest course of bricks, clean out the cavity of all debris, insert a new damp course, replace the bricks and then re-render or plaster once again, ready for painting.