- Retaining walls hold back soil, so water in that soil pushes against them.
- Without waterproofing and drainage, the wall stays wet, stains and can weaken over time.
- Treating only the exposed face hides the problem. Lasting work deals with water on the soil side.
- Describe the wall once and compare quotes from contractors across Cape Town.
Tell us about the problem and compare quotes from retaining wall waterproofing specialists in Cape Town.
Compare QuotesSigns You May Need Retaining Wall Waterproofing
- Damp patches, efflorescence or algae on the exposed face.
- Damp on the inside of a room where a retaining wall forms one side.
- Water seeping through joints or weep holes that are blocked.
- Cracks, bulging or leaning, which need an engineer before waterproofing.
Causes and What the Assessment Should Establish
- Whether the wall was built with a membrane and drainage behind it.
- Whether weep holes and drains are working.
- Where surface water from the slope ends up.
- Whether the wall is a garden wall or part of a building.
- Any structural movement.
Options and Their Limits
| Option | What it does | Limitations |
|---|---|---|
| Soil-side membrane | Waterproofs the wall where the water is | Needs excavation behind the wall |
| Drainage behind the wall | Relieves water pressure | Must have a working outlet |
| Clearing or adding weep holes | Lets trapped water out | Treats pressure, not dampness through the wall |
| Internal tanking on the exposed face | Holds water back where excavation is impossible | Water still reaches the wall |
| Sealer or paint on the face | Improves appearance | Short-term; can trap moisture |
Drainage is often part of the fix. See French drain installation and lateral damp treatment.
What the Work May Include
- Excavating behind the wall where access allows.
- Cleaning and priming the soil-side face, then applying a membrane and protection board.
- Installing drainage aggregate, a perforated pipe and outlet.
- Backfilling and reinstating gardens or paving.
- Repairing and sealing the exposed face.
Retaining Wall Waterproofing Prices in Cape Town
| Item | Ballpark price |
|---|---|
| Retaining wall waterproofing, per m² | R250 - R550 |
| Internal tanking on the exposed face, per m² | R800 - R1,500 |
| Drain behind or along the wall, per linear metre | R300 - R600 |
Ballpark figures, not quotations. Indicative 2026 ranges, rounded, from published South African damp-proofing, waterproofing and plastering price guides (Cape Town and Western Cape guides where available, national and Gauteng guides otherwise), checked October 2026. Per-metre prices are per linear metre of wall unless stated. Some include VAT and some do not, so confirm VAT on every quote. A site assessment and a written quote set the actual price.
What changes the price
- Wall height and length.
- Excavation depth and access for machinery.
- Drainage, outlets and reinstating the garden.
- Any structural repairs.
Getting Retaining Wall Quotes
Give the rough height and length, what is behind the wall and add photos. Compare quotes through Damp Proofing Cape Town.
Frequently Asked Questions
Can I waterproof a retaining wall without digging?
Partly. Internal tanking on the exposed face helps, but water still reaches the wall. Soil-side work lasts longer.
Why do retaining walls need drainage?
Water builds up behind the wall and adds pressure. Drainage releases it.
My retaining wall is cracking. Is that damp?
It could be movement. Get an engineer to check before waterproofing.
Does a garden retaining wall need waterproofing?
Not always. It matters most where the wall forms part of a building or water stains paving and walls.
Related Pages
Damp Proofing Cape Town is a free quote-comparison service. Damp is inspected, quoted and repaired by independent damp proofing contractors, and your agreement is with the contractor you appoint. Ask each one for a written, itemised quote, what is and is not included, guarantee terms and payment terms before paying anything.
Retaining Wall Waterproofing Cape Town. Describe the wall once and compare retaining wall waterproofing quotes.
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