Unfortunately, damage to homes and businesses many years after being built is unforeseeable. This is often due to the rising presence of damp, a plague in many South African homes and buildings, whether on the Highveld or on the Cape coastline and the ever present moisture in the air. To make matters worse, there are many diverse types of damp, each inflicting its own brand of property damage.

Thankfully, for all the types of damp there exists an equal proportion of remedies, offering homeowners, business owners, and developers an opportunity to rid their buildings of threatening damp.

Why treat the damp in my home or building?

Your home, commercial or industrial building (or several of them) are likely to be the largest monetary investments that you will undertake. Untreated damp problems will result in structural and cosmetic damage that will adversely affect the value of this investment and your ability to maximize your profit when you eventually sell this type of asset – an asset that should always increase in value!

Another perhaps more important reason to treat damp is due to the adverse health problems that it can cause you, your loved ones, employees and even customers (which in turn will impact negatively on your business).

Rising Damp

This type of damp is most often found in buildings occupying low-lying areas. Unfortunately, because of the rising value in property and an ever-growing urbanization in Gauteng province, many homes and businesses are built alongside rivers and marshland. Large volumes of water below-ground rise, and as a result filters into structures’ foundations and walls.

Common causes of rising damp include:

  • A Damp Proof Course (DPC) was not installed at the time of construction
  • The original DPC was not positioned correctly.
  • The original DPC has deteriorated due, for example, to house settlement, vibration from passing traffic, or general land subsidence. This is especially common where bitumen DPC has been used – Buildings built before the 1970’s in Gauteng are especially susceptible to this.
  • The damp course has been “bridged,” e.g. by earth being piled up against an outside wall

 There are several ways of recognizing rising damp:

  • Tide marks occur around walls within homes or buildings. These marks often don’t rise past a point as the water eventually evaporates. This generally occurs up to approximately 1.6m.
  • Plaster, paint and wallpaper will either bubble, crumble or break below the tide mark.
  • Skirting boards will likely rot, and wooden floors will swell, causing costly damage.

When it comes to rising damp in existing buildings, it means that the Damp Proof Course is either non-existent, or there are locations along the course that are weakened. For this reason, there is no quick fix for rising damp.

A damp specialist will need to be contacted, and brought in to locate the problem areas. Once this has been done, an effective chemical substitute and concrete layer will need to be reinforced to prevent rising damp. Royal Coat Africa prefers to use the Safeguard Chemicals range of Chemical DPC injection to create a chemical DPC once it has diffused into the brick and mortar – this will halt the rising damp. The affected areas can then be re-plastered with salt retardant additives (to eliminate hygroscopic salts), and once this has cured, the substrate can be restored and re-decorated.

Always contact a damp proofing specialist such as Royal Coat Africa when there is evidence of rising damp within your home or business!

Falling Damp

Falling damp is the ingress of moisture into a building from high areas (Roof areas, gutters, balconies etc) or in the case of boundary or parapet walls from the top of the brickwork due to inadequate waterproofing or bricks becoming porous with weathering – ever noticed paint peeling off your boundary walls?

Moisture ingress and resulting damp related damage caused to an internal wall from an inadequately waterproofed balcony above. This site is in Ferndale, Johannesburg.


Moisture ingress and resulting damp damage caused to an internal wall from an inadequately maintained box gutter, the box gutter had also rusted in places allowing rain water to penetrate the walls. This site is in Randburg, Johannesburg.


Moisture ingress and resulting damp damage and mould caused to a room. The balcony above was inadequately waterproofed during the construction phase and previous remedial damp proofing attempts had failed. This site is in Ferndale, Johannesburg.

As falling damp occurs from external sources (such as balconies, gutters) etc, these areas should be checked first when falling damp has been identified as the type of damp affecting your home or building.

Inspect these areas in detail – in the case of downpipes and gutters ensure that they are unobstructed – if these are damaged consider replacing them or if they are not too badly damaged consider waterproof repair – a service which Royal Coat Africa can offer.

In the case of walls inspect problem areas such as parapets and plaster cracks. In some cases your walls will have to be waterproofed and plaster cracks sealed – if the damage is too advanced walls should be re-plastered and the substrate re-decorated, again Royal Coat Africa has the skills and experience to offer this service and solution.

Always contact a damp proofing specialist such as Royal Coat Africa when there is evidence of falling damp within your home or business!

Penetrating Damp

Penetrating or Lateral damp is the horizontal ingress of moisture through walls – it is common in subterranean garages and basements where damp proofing on the positive side has failed or in non-existent in the first place.

Penetrating damp generally forms in the form of watermarks away from window, floor and roof areas. These patches become more prevalent in times of heavy rain – especially during the rainy season on the Highveld or during winter in the Cape.

The outcome of this type of damp is similar to all other types of damp:

  • Dead (rotten) plaster with decorative render “bubbling” off the wall and other forms of decorative spoiling
  • The formation of mould – causing health problems – especially respiratory issues such as Bronchitis.
  • Rotting skirting boards and plaster cornices

Structural damage over time – leading to loss in value of your asset. Perhaps even legal problems if you have not rectified or disclosed these problems to buyers.

The resulting damage caused by penetrating damp in a subterranean garage in Hyde Park, Johannesburg.


The start of the remedial repairs – removing dead and damaged plaster off the walls right down to the brickwork.


Treatment complete – re-plastering over the damp proof slurry. All that is left now is to redecorate with a render – in this case re-skimming and painting – skills in which Royal Coat Africa is extremely adept.

To effectively treat this type of damp, remedies may include the chopping off of plaster down to the brickwork and applying a cementitious slurry to waterproof the area, and re-plaster with a salt retardant mix. The insertion of a “fillet” may also be necessary to counter hydro-static pressure.

In most cases it will also be necessary to waterproof and stop the source of the water ingress where possible – or in the case of plumbing or a leaking roof being the cause of the damp, repair this aspect before attempting remedial damp or plaster repair.

Royal Coat Africa has the skills and experience to deal with penetrating and all types of damp!

Condensation Damp

Condensation within houses and commercial buildings is only going to increase as modern developments make use of heat-retaining construction materials. The warmer air created within buildings often holds water vapour that condenses on colder walls. In some areas of the home or office there is excessive amounts of water vapour, and in these instances condensation damp develops:

  • Black mould/damp develops on ceilings and/or walls.
  • Wallpaper can lift, becoming damaged in the process.
  • Damp can develop within walls and ceilings, not visible to people within the building.
  • This form of damp and mould can be harmful to residents as the mould releases spores into the immediate atmosphere causing lung infections and other diseases.

There are many ways of reducing condensation within the home. For instance, whenever steam is being produced in the home, ensure that there is always sufficient ventilation – for example the kitchen and bathroom!

Make sure that there is also plenty of open space within the home, and that no clothing is dried indoors. Alternatively, commercial property will have to be properly fitted with ventilation fans to reduce condensation.

When condensation creates excessive damp within walls and ceilings, professional assistance will be required to eliminate the damp, and use the correct chemicals to protect the integrity of the building from further damp incursion.

Chemical Damp

This form of damp is commonly associated with hasty workmanship by plasterers and coating specialists. Often within the South African context plaster is mixed incorrectly (due to inadequate skills or training), and compounded by insufficient curing methods and curing times.

The hygroscopic salt within the coatings or plaster absorbs water vapour within the surrounding atmosphere, creating a similar damp issue to that of condensation damp. The major difference is that chemical damp will occur directly on the affected plaster or concrete, creating angular dimensions to the extremity of the damp patch.

In cases of chemical damp there can only be one solution; hygroscopic salts within the plaster will only continue to attract moisture, increasing levels of damp and mould. The problematic plaster or concrete coating needs to be removed from the substrate and reapplied using a salt retardant mix to ensure that the chemical damp does not occur again. After this phase, the plaster can be redecorated with an appropriate render

Make sure that you contact your damp proofing specialist such as Royal Coat Africa for assistance with your chemical damp problem.

The final word on damp…

Damp can affect homes and commercial buildings that are located far from low-lying wetlands. In fact, those buildings found in dryer areas are not built to withstand large volumes of water. In the event of flooding, or excessive condensation, damp can spread a lot quicker as the correct waterproofing and damp proofing measures may not have not been installed.

Make sure that you remain aware of evidence of damp at home or in your offices or commercial properties. It is important that you find a damp proofing expert such as Royal Coat Africa that understands the different types of damp, and has knowledge of and experience in damp repair methods.

If you require damp proofing in Gauteng, do not hesitate to contact Royal Coat Africa as soon as possible. Visit our damp proofing page for more information regarding our damp proofing services and to get in contact with us to assist in the resolution of your damp problems!

Alternatively, take a look at our damp proofing and waterproofing services here