What Is Rising Damp?

Rising damp is the moisture deposited in walls after rising from the ground through the fabric of the brick. The water rises through capillary action and is stored at a height where gravity counters the upward force, usually at 1.2 m.

The effects of the rising damp are visible and much higher. Wallcoverings like plasters, vinyl wallpaper and paints diffuse the damp farther and deposit salt much higher along the wall.

What Is Penetrating Damp?

Penetrating damp, or lateral damp, is the development of moisture through the walls of a building. Although common in old buildings, lateral damp has been observed on newer structures, at any level.

Penetrating damp is quite common in buildings with poorly installed cavity walls. Water can bypass a cavity wall where the tiles are improperly positioned and through mortar obstructions.

Rising and Penetrating Damp Prevention and Treatment Services in London

  • 01Rising & Penetrating DampRead more
  • 02What Is Penetrating DampRead more
  • 03What is Rising DampRead more
  • 04Causes of Rising DampRead more
  • 05Causes Of Penetrating DampRead more
  • 06Symptoms of Rising dampRead more
  • 07Symptoms of Penetrating DampRead more
  • 08Rising Damp vs Penetrating DampRead more
  • 09Stop Penetrating DampRead more
  • 10Stop Rising DampRead more
  • 11What is a Damp Proof CourseRead more

What Are the Causes of Rising Damp?

Water rising in a wall causes rising damp. Many buildings have installed barriers to stop rising damp. The barriers are called Damp Proof Cause and are made of water-resistant material like bitumen, slate or plastic. The type of material used largely depends on the time the building was put up.

Some old buildings do not have DPCs installed at all, and with some buildings, these barriers fail with time. In the absence, or with evident proof of the failure of the present DPCs, there is nothing preventing water from rising your wall. Some DPCs can be bridged. This happens when moisture travels past the DPC barrier because of construction failure.

It is vital that you locate the cause of your damp to deal with the effects. This will prevent further damage and recurrence in the future.

What Causes Penetrating Damp?

Penetrating damp is caused by several building defects. Old porous bricks, bricks destroyed over time by frost, weakening of mortar joints, faulty brickwork between bricks and windows or doors, and leaking roofs or pipes.

These defects allow water to soak through the wall. Penetrating damp also occurs where the external wall is higher than the internal wall. That is common with cellars and basements. The water in the soil in contact with these walls penetrate the brickwork.

How Can You Be Sure You Have Rising Damp?

Rising damp is different from other damp issues in many ways. The most obvious sign is the distinctive tide mark visible on the affected wall where the damp dried out through the brick. Rising damp also deposits nitrates and salts on your wall, up from the ground.

How Can You Be Sure You Have Penetrating Damp?

The most indicative signs of penetrative damp are damp patches on the internal walls of buildings. These patches are separate from ceilings, doors and windows. They grow more prominent if the source of the damp is not identified and are more prevalent during the rainy season.

The building will also develop a musty smell and mould growth, depending on the conditions. In severe situations, you may notice free-flowing water on the surface or water droplets. Penetrating damp does not leave salt deposits.

If you see these signs, you need to identify the source of the damp. Also, look at your plumbing for defective signs or burst pipes.

What Is the Difference between Rising Damp and Penetrating Damp?

Different buildings will have various damp issues. That is why we offer a range of services for different problems. Rising damp occurs at the ground floor level as water from the soil outside is drawn up the walls through capillaries in the masonry. Often rising damp is mistaken for condensation Penetrating damp is caused by water that has entered a building through ceilings, roofs or floors. It happens at any level, unlike rising damps, and are much more likely in older structures that have solid walls.

We Offer Professional Damp Treatment

At Southern Damp Proofing Damp Proofing, we offer professional treatment for penetrating and rising damp. We tackle the damage caused by either the absence of a physical damp treatment course or the ineffectiveness of the existing one.

We will survey the property for the source of dampness. Starting from the ground floor and working upwards, we guarantee that we will find any signs of penetrating damp, rising damp, defective plumbing, high external ground levels and bridged physical damp course. Additionally, we inspect the building’s ventilation for any signs of condensation.

After our diagnosis, we provide a full report on the situation at hand and offer remedies to each problem.


Is penetrating damp dangerous?

Penetrating damp is not generally considered dangerous. However, depending on the inherent health situation, it might pose a risk to some individuals. The sick, young children and infants and the elderly are prone to develop conditions like asthma, flu or complications from exposure to mould.

What does rising damp look like?

Rising dap manifests as tide marks along the walls, decaying skirting boards, peeling wallpaper and bubbling plaster.

How much does it cost to treat rising damp?

The cost of treating rising damp depends on the extent of your problem, the size of the building and the cause of the damp. Note that prices tend to be higher by 20% around London.

What causes rising damp in internal walls?

Rising damp is groundwater rising through the capillaries in brickwork. The reason for this is either the failure of the existing damp proof course (or absence thereof) or a rise in the ground around the walls. In older buildings, failed damp proofing course is common.