Rising damp is groundwater climbing your wall because the original moisture barrier has failed or was never there. You cannot fix it with a tin of paint. Here is what actually works, in plain terms, for a Cape Town home.
Genuine rising damp shows a tide-mark up to about a metre from the floor, worst at skirting height, often with a white salty crust and bubbling paint. If your damp is high on the wall, in cold corners, or sitting behind furniture, it is more likely condensation or penetrating damp, which have cheaper and completely different fixes. A specialist confirms it in minutes with a moisture meter, so do not start treatment on a guess.
Paint is a cosmetic cover, not a cure. The salts the rising moisture carries into the plaster keep pulling water out of the air, so within a season the damp and the blistering push straight back through the new paint. Treating the cause, not the stain, is the whole game.
A proper repair runs in order: diagnose the cause and rule out high ground levels or leaking downpipes outside, install a new chemical damp-proof course by injecting a silicone cream or fluid into the mortar near the base of the wall, hack off the salt-contaminated plaster above the tide-line, then re-plaster with a breathable, salt-resistant render. Skipping the salt-plaster removal is the number one reason a treated wall looks damp again.
Rising damp is often made worse by things outside the wall: a garden bed or paving built up above the internal floor level, a leaking gutter or downpipe soaking the base of the wall, or a path that bridges the old damp-proof course. A good specialist checks and corrects these, because a new DPC alone will not hold if the wall keeps getting fed from outside.
In Cape Town in 2026, a chemical DPC injection runs about R350 to R750 per linear metre, and the full treatment including re-plaster is about R450 to R1,100 per linear metre. A single room is usually R6,000 to R15,000 fully treated. The new plaster then needs to dry, roughly a month per coat, before you paint it with a breathable paint.
You can fix the external causes yourself, lowering a high garden bed, clearing a blocked gutter, redirecting a downpipe. The damp-proof course injection and salt-resistant re-plaster are specialist work, because the barrier has to be continuous and the plaster system has to be right, or the damp returns. Most lasting repairs are a specialist job.
The new barrier works immediately, but the wall has to dry out, which takes time because it has been wet for years. Expect the wall to keep drying for several weeks to a few months, and only re-paint once your specialist confirms it is dry, using a breathable paint.
Reputable specialists guarantee a chemical DPC for 10 to 20 years, but the guarantee only holds if the salt plaster was removed and re-plastered properly and the external causes were corrected. Always get the guarantee in writing and keep the invoice.
Tell us about the problem and we'll connect you with one trusted local specialist for a free, no-obligation quote.