Rising damp or penetrating damp – what is the difference?

Home » Rising damp or penetrating damp – what is the difference?

How do I know if my property has penetrating damp?

Penetrating damp is caused when rain water penetrates the external brickwork of your property and transfers through to the internal wall. Signs of penetrating damp can appear at any level of your property, including ceilings, so if you’ve spotted patches of damp on a level higher than the ground floor, then penetrating damp is likely the cause.

Common causes of penetrating damp include:

  • Blocked gutters and damaged downpipes
  • Old and damaged exterior brickwork
  • A burst water pipe
  • A roof leak
  • Blocked air bricks

How do I know if my property has rising damp?

Rising damp is caused by the presence of a faulty or ineffective damp proof course in your property. Brickwork is naturally porous, which means that it absorbs ground water through capillary action – just like a sponge. This water then tracks upwards through the brickwork as it tries to evaporate.

As such, rising damp will only ever occur on the ground floor of your property, usually appearing as a distinctive tide mark up to 1.5m from the base of the wall. If you spot damp patches on the second floor or higher, it is not the result of rising damp and is instead likely to be the result of penetrating damp or condensation.

An effective damp proof course prevents ground water from making its way through to your internal wall, so if you suspect your property has rising damp then don’t hesitate to contact our specialists in damp proof course repair.

Both rising damp and penetrating damp can be dangerous

Despite their differences, both rising damp and penetrating damp are serious damp problems which are not only ugly to look at but can negatively affect your health. It’s therefore important that you seek to treat rising damp and penetrating damp as soon as it appears.


Contact our damp specialists today on 01202 737739 for professional damp proofing and damp treatment services for rising and penetrating damp. We are highly experienced in handling all types of damp and will identify the best method for tackling your damp problem in an effective way.

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