What is rising damp?

Rising damp is the process where moisture from the ground surrounding a property is absorbed upwards into the porous structure of the building walls.

Excess ground water and leakages from other sources can often expose bricks/masonry to enough moisture that it 'wicks' its way upwards through a process known as 'capillary action'. This process is very much like how a cloth touching a pool of liquid will draw up the fluid, even if the cloth is entirely vertical.

Most modern properties built within the last century or so will have a layer built in to the walls near the ground to stop this process in its tracks. This is known as a Damp-Proof Course (DPC).

What is penetrating damp?

This kind of damp is also known as 'rain penetration' and describes water leaking into the building from outside.

Common sources of water ingress are:

  • Broken or missing gutters and downpipes
  • Cracks in rendering or masonry
  • Damage to brickwork and pointing
  • Porous bricks or poor quality mortar
  • Cracked/damaged roofs or missing roof tiles
  • Faulty/blocked drainage systems
  • Non-breathable outer wall coatings/paint
  • Broken or missing windowsills

The problem is often more prevalent during periods of extended wet weather.

What are the health implications of damp?

If your home is currently showing any signs of damp you will be well aware how unattractive it looks but it's not just an aesthetic issue.

Persistent damp often gives rise to mould, affecting respiratory systems and contributing to conditions such as asthma.

Some moulds can produce allergens, irritants and toxic substances, so Inhaling or touching mould spores may cause allergic reactions in some people.

How is damp identified?

At London Damp Proofing, we use a variety of specialist tools and techniques to locate and identify damp, including moisture meters, sample analysis and knowledge of different symptoms.

Our years of experience and training help us to offer the quickest and most cost effective solutions for every property and damp issue.

What is a Damp Proof Course?

A damp-proof course (DPC) is a barrier integrated into a property's walls, with the purpose of preventing moisture rising upwards inside the porous brick structure and causing rising damp.

A damp proof course is usually laid horizontally, but can occasionally be vertical. The DPC layer is usually laid below any masonry walls that make contact with the ground around a property.

You can usually see a DPC as a dark line running along the bottom of a brick wall, sometimes a layer or two up.

What types of buildings are affected by damp?

Damp issues are not always limited to older properties. Rising damp is less of an issue in newer properties that must be built with a Damp Proof Course, but other forms of damp can be found in all types of building.

Properties with outer walls exposed to regular adverse weather may not be built to a specification that prevents penetrating damp.

Properties with cavity wall insulation can sometimes encounter issues where the insulation bridges the gap between inner and outer walls, allowing moisture to cross to the interior.

Issues with poorly fitted, faulty or damaged guttering can affect even the most modern homes, and this is a very common source of water entering a property.

How much does damp proofing cost?

This is a common question asked by clients.

Since every property is different in size, age, construction and usage, the cost for damp proofing can vary a great deal. This makes it difficult to offer a quote until our trained inspectors have surveyed your property and evaluated the problems.

Your best approach is to give us a call on 020 7593 8030 or fill out our contact form, then we can organise a free survey as soon as possible.