How to Treat Rising Damp in South Africa: Step-by-Step

Rising damp is the single most common wall failure in SA homes older than 20 years. The good news: it's completely fixable in a weekend if you follow the right sequence. Skip a step and you'll be redoing the job in 12 months.

Step 1: Confirm it's actually rising damp

• Tide-mark stops at roughly 1 m off the floor (higher = penetrating damp).
• White salt crystals (efflorescence) along the skirting.
• Paint bubbling from the bottom up, not from a ceiling leak.
• Wall feels cold and slightly damp to the touch on hot days.

Step 2: Strip back to bare brick

Chip off any blown plaster to at least 300 mm above the damp line. Brush off loose salts with a stiff wire brush. Do not skip this: sealing damp plaster in traps moisture behind the treatment and the wall fails again.

Step 3: Apply Damp Gone Xtreme

Two saturating coats, wet-on-wet, with a masonry roller. One 5 L kit treats roughly 25 m². Full application walkthrough is on our DIY damp proofing kit page.

Step 4: Wait, then replaster

The wall needs 4–6 weeks to release the trapped moisture before you replaster. Use a salt-retardant plaster (SABS-approved) for the first 20 mm, then finish normally. Paint only after another 2 weeks.

Treating rising damp on internal walls

Internal walls are where rising damp shows up first and worst. Bedroom skirtings start lifting, plaster crumbles behind the bed, and the wall behind your TV unit grows a halo of dark patches. The good news: treating rising damp on an internal wall is one of the most DIY-friendly jobs in home maintenance, if you follow the right sequence and don't skip the prep.

How do you know it's rising damp and not something else?

Rising damp has three tell-tale signs that almost never lie:

• A horizontal tide-mark between 200mm and 1m off the floor, never higher.
• Salt deposits (white powdery efflorescence) along the skirting that come back even after you wipe them off.
• Damage worse in winter and spring, when the soil is still wet from summer rain.

If your damp patch is up near the ceiling, around a window, or only behind a shower, it's probably penetrating damp or condensation, not rising. Read our mould and condensation guide for that scenario.

What you'll need (R1,500 budget, 1 weekend)

• Damp Gone Xtreme 5L kit (covers ~25m² of wall, inside + outside if you can access it).
• Wide paint scraper and 80-grit sandpaper.
• Dust sheet and masking tape.
• Cheap 100mm paint roller and a 50mm cutting-in brush.
• P2 dust mask and nitrile gloves.
• Bucket of clean water and a sponge.

Step 1: Strip back to a sound surface

Move the furniture away from the wall and lay down dust sheets. Scrape off all flaking paint, blown plaster and loose render up to at least 300mm above the visible tide-mark. If the plaster sounds hollow when you tap it, it has to come off. Xtreme treats the brickwork behind the plaster, not the failed plaster itself. Vacuum the debris and wipe the wall with a damp sponge to lift loose salts.

Step 2: Treat the bottom 1m of wall, inside and out

Stir the Xtreme thoroughly. Pour a small amount into a roller tray and apply two saturating coats to the bottom 1m of the wall, wet-on-wet, put the second coat on within about 2 minutes of the first, while it is still wet. The liquid should soak into the brick, if it beads off immediately you've got paint or sealant in the way and need to strip more. Don't dilute it. Don't skimp at the corners.

For best results, treat the outside face of the same wall as well. Rising damp comes through from both sides of a single-brick wall, and treating only one face leaves a moisture path. If the outside is rendered, our crews handle this on every professional damp proofing job.

Step 3: Wait. This is the step everyone skips.

Brickwork that's been wicking moisture for 20 years has a lot of trapped water and salts to release. After treatment, leave the wall bare until it has dried out properly before replastering (allow at least 2 days before painting any treated surface). Open windows daily. If you replaster too soon, the salts come straight through your new finish and you'll think the treatment failed, it didn't, you just sealed wet brick.

Step 4: Replaster with a salt-retardant render

Once the wall reads dry on a moisture meter (20% or less), replaster with a salt-retardant render, your local builder's merchant stocks it as 'waterproof plaster' or 'render additive'. Standard cement plaster will let salts through. Skim, sand and paint with a breathable interior paint.

When to call a professional instead

• Double-storey wall or anything above 2.5m on the inside.
• Wall shared with a bathroom or kitchen with active leaks.
• Heritage home with hand-pressed bricks or lime mortar.
• Damp that's already caused floor or skirting rot.

In any of those cases, book a Professional Inspection, via our professional damp proofing service or WhatsApp 061 589 8070. Otherwise grab a Damp Gone Xtreme DIY kit and knock it out this weekend.

When to call a pro instead

External walls above 2.5 m, double-storey, or heavy salt damage needing replaster, book our professional damp proofing service with a written 6-month workmanship guarantee. Also see our DIY vs professional guide.