Penetrating Damp

What is Penetrating Damp?

Penetrating damp refers to the ingress rainwater above ground at various points in the external envelope of the building through roofs, walls, chimneys and openings such as windows and doors. This includes spillages from gutters and down pipes.

Typical Visual Image


What are the signs of Penetrating Damp?

  • Damp staining on external ceiling and/or wall surfaces corresponding to defect in the external roof, wall and/or rainwater disposal fitments 
  • Damp patches on internal walls and ceilings
  • Visible damp or wet and crumbling plaster work 
  • Black mould growth isolated to one area
  • Dripping water and/or pooling water
  • Rainwater penetration can be damaging to a property even if it does not penetrate all the way through a wall on a property.
  • Poorly installed wall-ties or cavity wall insulation can provide a pathway for rain penetration to track through cavity walls
  • Moss growth, excessive heat loss frost damage.

Note: Penetrating damp can occur in buildings of all ages.



If you experiencing any of these problems
an ISSE Member may be able to help

If you like to learn more
there are a wide range of training courses available with the ISSE