Rising Damp in Ekurhuleni: Lessons from Fairleads to Pomona

I have just finished tackling a persistent rising damp problem for a client – William – in Fairleads, Benoni. This part of Ekurhuleni is notorious for its wetlands, meaning the water table often sits perilously close to the surface. The problem was so severe that every ground‑level room in his property was affected. In fact, as we chipped off the old plaster from the affected walls, the bricks and mortar were visibly saturated, still actively sucking moisture from the soil below. That sight alone told us exactly which remediation method was needed.

One the affected interior walls

And just to show how prevalent this issue is across Ekurhuleni: a few weeks after fixing William’s damp problem, I met another client – Nothando – to effect some key alterations on her kitchen cabinet units in order to accommodate a new dishwasher. However, during our conversation, she raised a similar issue with her own property, this time in Pomona. Her home, like William’s in Fairleads, sits on the same vast, interconnected stretch of wetlands – part of the Blesbokspruit wetland catchment, one of the most significant wetland systems in Gauteng, with a section even designated as a Ramsar site for its ecological importance. We agreed that she would call me to diagnose the specific problem when she elects to attend to it. Until then, the exact method of remediation remains undetermined – because a thorough assessment must come first.

This experience – with William’s clearly diagnosed and cured damp, and Nothando’s future assessment – is the perfect starting point for a deeper look into rising damp: what causes it, how to spot it, and – most importantly – how to cure it for good.

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What Actually Is Rising Damp?

Rising damp occurs when groundwater is drawn vertically up through porous building materials like brick, mortar, and plaster via a process called capillary action – the same way a sponge draws water from a wet surface. It primarily affects older buildings constructed before modern damp‑proof courses (DPCs) became standard, or properties where the existing DPC has failed or been bridged.

The moisture carries soluble salts from the soil. As the water evaporates from the wall surface, these salts are left behind. Over time, they accumulate, crystallise, and expand, physically destroying plaster and paint from within. The result isn't just unsightly – it's a structural and health issue.

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Signs of a Problem

If you suspect rising damp, look for:

1. Tide marks or damp patches rising no higher than about 1.2 metres from the floor.
2. Peeling or blistering paint near skirting boards.
3. White, powdery salt deposits (efflorescence) on wall surfaces.
4. Rotting skirting boards.
5. A persistent musty odour.

If you see these signs, painting over them will fail every time. The moisture will simply push the new coating off, and the salts will continue their destructive work behind the scenes.

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The Three Core Remedial Methods

There are three main approaches to stopping rising damp. The choice depends on the wall construction, the severity of the problem, and the building's age.

Method 1: Chemical DPC Injection

This is the most common and cost‑effective solution for most homes. Holes are drilled at regular intervals (typically 100–120mm apart) along a horizontal mortar course, about 150mm above ground level. A high‑strength silane/siloxane cream is then injected under low pressure. The cream spreads through the pores of the masonry, reacts with the silica in the mortar and bricks, and cures to form a waterproof barrier that permanently stops the capillary rise of moisture.

Method 2: Damp‑Proofing Rods

Functionally similar to the cream, damp‑proofing rods are solid, porous cylinders pre‑dosed with a water‑repellent agent. After drilling identical holes, the rods are inserted. Over time, they slowly release their active ingredients, which diffuse into the surrounding masonry to form the DPC. This can be a less messy option, but it relies heavily on consistent mortar quality and correct installation.

Method 3: Electro‑Osmotic Systems

This is a specialised, low‑voltage system, ideal for walls that don't respond well to chemical treatments – such as thick rubble‑filled stone walls over 600mm wide. A series of titanium anodes are inserted into the wall and connected to a small control unit. This creates a minute electrical charge that positively charges free moisture molecules. These are then repelled from the anodes and attracted down towards a copper‑coated cathode rod buried in the ground outside. It is a chemical‑free, low‑energy system with a long track record of success in challenging structures.

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The Complete, Permanent Fix

Installing a new DPC is only part of the job. A thorough, lasting repair requires a multi‑step process.

Step 1: Remove Contaminated Plaster

All salt‑laden plaster must be hacked off, to at least 300mm above the highest visible tide mark. This is non‑negotiable. Leaving contaminated plaster will sabotage any new DPC.

Step 2: Install the New DPC

With the wall stripped, install your chosen DPC – whether injection cream or rods – following the manufacturer's specifications precisely.

Step 3: Apply a Salt‑Retardant Render with Cement Additives

After allowing the new DPC to cure (a minimum of 14 days), the wall must be replastered with a specialised salt‑retardant and waterproofing additive. Products like Coprox cement additives – or similar waterproofing compounds such as Permaproof or Renderguard Gold – are mixed into a sand‑cement render. This render acts as a secondary defence, actively resisting the capillary rise of any residual salts and moisture, and sealing the wall against future wicking.

Step 4: Use Breathable Top Coats

Finally, finish with a breathable, moisture‑resistant paint. Standard emulsions will trap moisture and fail.

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A Regional Problem, A Disciplined Approach

The Blesbokspruit wetlands do not discriminate. From Fairleads to Pomona, from Germiston to Kempton Park and beyond, rising damp is a persistent threat. William’s walls were visibly wet – and after proper diagnosis, we fixed them. Nothando’s property in Pomona shows similar distress, but we have not yet assessed it. She will call me when she is ready, and only then will we determine the right method.

The principle remains: diagnose accurately, treat methodically, and finish correctly. No shortcuts. No guesswork.

Rising damp isn't a mystery, and it certainly isn't a life sentence for your property. It is a clear, predictable process – and once you understand it, you can stop it in its tracks.

If your walls are showing those tell‑tale tide marks, don't just paint over them and hope for the best. Call someone who can diagnose the problem correctly and implement the right solution – with the correct DPC, a salt‑retardant render, and cement additives like Coprox where needed.

For William – and for Nothando when she is ready – the approach is the same. That is how you turn a damp, crumbling wall into a solid, dry one.

Remedied wall, after damp treatment, replastering and skimming. Ready for painting 

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For further details on my damp‑proofing, waterproofing, and home renovation services, please reach out.

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