Dampness in walls? Let’s deal with it

Nice house, beautiful memories, perfect view, but oops, damp walls all around!
Demolishing your house is not the solution! It is critical to first assess the condition of the existing wall before selecting a solution for the dampness problem.

In the 1900’s, traditional building in the UK involved bricks and water with single leaf solid walls. Bricks are absorbent materials that slowly absorb humidity and water whenever exposed to them. The single leaf solid walls comprised of one layer of bricks that separated the indoors from the outdoors but were greatly affected by capillarity.

After this, cavity walls were introduced, having 2 layers of bricks with a cavity/space in the middle that served as a natural runoff for any water that ran in. Weep holes were embedded at the base to allow the water in the cavity to escape out of the wall structure as well as evaporated water.

Despite any strong materials used in a structure, dampness when identified in buildings requires urgent attention. If ignored, the structural integrity and strength of the building gets compromised overtime i.e.

  • Decay in timbers in contact with wet masonry
  • deterioration of the external fabric of the wall due to freezing and thawing
  • Accumulation and movement of salts and other chemicals within the walls thus causing wall stains
  • Growth of molds on the inside surfaces of walls
  • Corrosion of metals with the wall


Medicine is prescribed after diagnosis, likewise, a building solution is decided after inspection of the building in question. The following need to be assessed prior to applying any dampness solutions;

  • Is there an existing external plaster on the wall or is it exposed brick or stone?
  • Is the existing plaster lime or cement based?
  • How exposed is the building to the ground water table?
  • What is the moisture content of the damp wall?
  • If accumulated with salts, you might need to know the types of accumulated salts.
Posted on: December 4th, 2021 by London Building Contractors No Comments

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