Damp - water you going to do?

Damp refers to the presence of moisture, water, and condensation being present within a property. Dampness occurs quite frequently in different properties but tends to be commonplace in those that are older or have not been properly maintained.

Rising Damp

Rising damp is perhaps the scariest type of damp for all prospective homeowners or first-time buyers. Rising damp particularly occurs in older properties, where a lack of effective DPC (Damp-Proof Course) allows water to rise up through floors, walls, and masonry. Bricks and mortar can be porous, allowing the water to travel up the minuscule holes and into your property.

These are the common symptoms of rising damp in your property:

  • Tide marks on the wall, up to one metre high, which leave a visible residue of water and salts
  • Smells or a musty odour
  • A reduced temperature at the lower portion of the wall
  • Rotting of embedded floor timbers
  • Crumbling or blistered plaster due salt crystallisation

Walls are then often contaminated with salts that mean it is not possible to just re-plaster and hope the problem will go away. The best method is to remove the plaster on offending walls to about 1.2m in height, dry and re-plaster. Liquid DPC’s can then also be injected.

Penetrating Damp

Penetrating damp is the most common form of water-ingress in your property – but is particularly prominent in buildings with solid wall construction or cavity walls where the insulation has been fitted incorrectly or in unsuitable walls. It is caused by water permeating through walls from the outside.

These are the common symptoms of water penetration in your property:

  • Localised Dampness – Dark patches on external walls
  • Plaster Damage – Plaster & paint deterioration, blistering, the appearance of stains & salts
  • Wet Rot — Rotting skirting boards or timber
  • Moss — Excessive moss growth on external walls.
  • Brick Deterioration — Moisture entering the brick (spalling) causes surface damage
  • Mould — Mouldy scent or signs of mould growth on internal surfaces

The most common way to tackle penetrating damp is by painting exterior walls with a clear waterproof masonry coating.

Condensation

Excessive condensation simply caused by too much water vapour inside the house, usually due to poor ventilation or as a result of another form of dampness. Condensation occurs in properties of all ages and occurs when this warm water vapour hits a cold surface, like a window.

  • Steaming windows
  • Patches on walls, particularly occurring behind furniture and in corners.
  • Peeling wallpaper
  • Black spots on window and door frames
  • Mould growth (usually black mould)
  • Soft furnishings and fabrics prone to mould and mildew

Black mould is a potentially life-threatening issue for a young child, the elderly or anybody with a pre-existing lung condition. The most common way to remedy condensation dampness is by installing more effective methods of ventilation.