Prevention & Long-Term Care

A proper repair can last for decades, but rising dampRising dampMoisture from the ground that climbs up inside walls through the pores of the materials. It shows as stains, blown render and salts at the foot of walls. also has an external dimension that's often overlooked: what happens around a building affects what happens inside its walls just as much.

The ground level around a building plays a decisive role. Over the years, resurfaced pavements, accumulated garden soil, or a poorly graded yard can raise the ground level above an existing damp-proof membrane, effectively bypassing it entirely. Keeping a gap of at least 15cm between the soil and the start of the renderRender (plaster)A layer of mortar (sand, cement or lime, and water) spread over brick or concrete to give a wall a straight, sound surface ready for paint or tiles. goes a long way toward prevention.

GuttersGutter and downpipeThe channel and pipe that collect rainwater from a roof and carry it down to the ground or the drains. and rainwater downpipes need to discharge well away from the foundations — at least a metre — rather than directly beside the wall. A blocked or crackedCrackA split or gap in render, concrete, a wall, a coating or wood. Fine cracks are usually only on the surface; ones that grow, keep reopening or run diagonally need attention. drainpipe can turn one spot on the foundation into a permanent moisture source, undoing even the best repair.

Finally, after any treatment, it's worth doing an annual visual check of the areas that had problems, especially after periods of heavy rainfall. If you notice any of the early signs described earlier reappearing, catching it early in one small spot is always cheaper than redoing the work across the entire wall.