Rising Damp

Rising damp refers to moisture that gets rises up from your ground beneath the walls and into the walls, through its fabric. It can rise through block, brick or stone. The means by which it does this is capillary action. Water gets sucked in through small holes in the walls. The water will not go all the way to the roof but it will affect the strength of the walls because it gets up to about 1.2 meters. You will see whitish substances that are salt deposits much higher than this if you have walls that do not have space to breathe. Such walls are usually covered in vinyl wallpaper, plasters that do not breathe paints and renders. Wall damp causes structural damage when not mitigated properly. Damp proofing is one way to go when you want to solve this problem.

Bridged Damp Proof

This is a situation where the damp successfully travels through the DPC because of a fault in the construction. If the course has been bridged, there could be external additions like a flowerbed or a new patio that could be creating humidity and condensation. This increases the concentration of water that could get past the level with the DCP and into the walls. Most of the time, clearing out whatever might be causing this bridging will solve the damp rising issue.

Some of the things that cause this include:

  • Plasters overlapping the DPC (internal and external renders)
  • Debris in the wall cavity or subfloor void
  • Wrong insulation material in the wall cavity
  • Having solid floors

If you can eliminate anything that might be bypassing the DPC and letting moisture go straight into the walls, you will have solved this problem.

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

Damp Proof Course Failure

Sometimes, the Damp Proof Course fails. That calls for repairs. As always, it will be best if you get in touch with a professional or professionals who will do the damp treatment job with skills. The process includes an evaluation of the extent of the damage and what can be done to make sure that it does not get out of hand. Sometimes, you may have done a damp treatment before and it did not work.


A house is built to be weatherproof. We frequently use mineral paints, emulsion paints, high strength concrete, waterproofing and dehumidifiers to keep the structure’s integrity intact. However, they sometimes fail to work as expected. The roof might leak due to lose or broken tiles, gutters can get clogged with leaves and divert water (moisture), into the walls. Then the heat comes in with the sun and causes the moisture to condense in places where it creates even more leaks. Your mortar could be old or damaged too. The central pipework in the house can also be trickling water into the walls.

Very Old Homes

Rising damp is common in old homes from the 20th century or earlier. Modern houses have the Damp Proof Courses built into the foundations directly preventing this. The damp proof courses in older homes are used in small amounts and might not even be part of the construction at all. The older brick walls are heavily porous and will absorb the dampness as it rises from the ground or the condensation in the basement. In recent homes, there are problems caused by making it hard for the walls to breathe. Windows, doors, modern plaster and insulation, all cause the walls to trap moisture in the walls and it goes up higher.

The Signs Of Rising Damp

The most obvious signs are the damp problems. Apart from this, you might also see:

  1. Black spots that are mould might appear on the areas where the dampness is concentrated in the walls.
  2. You can also touch the walls without needing any professional help and be able to tell if they have been invaded by moisture. Just look at them and then touch them. Do they feel cold? Is there moisture on your hands or the wall? These questions are based on observations.
  3. You will see dampness, staining, lines, salt-like deposit and mould on the lower parts of the wall. Usually, this is about a meter from the ground.
  4. If you look at the floor and it appears to be lifting, you should probably check it out to make sure that your waterproofing has not been compromised.

As always, it is recommended that when you feel like the effects are adverse, you should call an expert or experts to come to check it out and see what is happening. Rising damp can cause toxic moulds that might not be good for your health when inhaled or touched.

What Do You Do About Rising Damp?

If you do not treat it, it can lead to structural failure and damage. The damage sustained is usually in the flooring, the plaster and the finishing. The smell makes it very hard to live with. Rising damp will affect your health in many ways and make respiratory conditions exacerbate. Heat loss is also a problem and that drives up the energy bills.

Therefore, the best thing to do is to treat the walls. There are levels of damage that you can DIY. However, with situations of improving ventilation, dehumidifier application, condensation treatment and other specific minutiae, you will need to call in the experts.


How is Rising Damp a Problem?

The worst case scenario is having structural damage to the house and because it happens in the lower levels next to the ground, could lead to a smell that comes from the walls as they become mouldy. This could present toxins and respiratory dangers. The dampness also decreases thermal insulation of the walls and this leads to higher energy bills to stay warm. Your health, your house and your bills could all get negatively affected.

How Do I Know It is Rising Damp And Not Just Wetness?

The most common signs that are very characteristic include tidemarks left on the walls. This is caused by evaporation of water and salts from the ground. They could be as high as a meter off the floor. You will also see stains and damp patches behind the plaster.

How Can I Find Out The Cause Of Rising Damp In My Walls?

The best way for you to know is to get an expert who will be able to check the sources properly. Guesswork is not an option. Condensation and penetrating damp are the most common sources.