Penetrating Damp

Penetrating Damp

It is typically caused by rain penetrating the structure of a building. The rainwater can soak through the external structure of the building and travel to internal walls and ceilings.

What is it?

It occurs when there are defects to your property on the outside such as missing tiles on your roof. These allow water to pass from the outside to the inner surfaces of your home such as ceilings or walls.

How is it caused?

It is normally a result of a defect outside your home such as:

• Missing roof tiles
• Blocked/defective rainwater goods
• Missing pointing
• Cracked rendering
• Gaps around doors and windows

Where is it found?

It can be found in different areas of your home. For example, there may be penetrating damp to the ceiling caused by a leaking roof or on an external wall due to a defective guttering causing water to run down the wall.

How to spot Penetrating Damp

• It usually appears as an obvious ‘damp patch’ that will look and feel damp to the touch.
• There may be damage to decoration, plaster, and walls.
• Penetrating damp is far more noticeable following rainfall.

It is rare to see black mould on areas of penetrating damp as the area is usually too wet. The damp area contains salts which are picked up as the water passes through the surface. These salts stop black mould from growing.