Foundation Waterproofing South Africa: below-ground walls and foundations take on moisture from the soil, leading to damp, peeling paint and leaks in basements. Compare quotes from specialists for membranes, tanking and foundation wall waterproofing.
- Photograph damp patches and note when they get worse.
- Say whether the wall is below ground on the outside.
Describe the job once and compare quotes from independent specialists.
Compare Waterproofing QuotesSigns of Below-Ground Moisture
- Damp or tide marks low on walls.
- Peeling paint, bubbling plaster or white salt deposits.
- Water seeping into basements or below-ground rooms.
- Musty smells and mould near floor level.
What the Work Involves
For external waterproofing, soil is excavated next to the foundation wall, the surface is cleaned and repaired, and a membrane or tanking system is applied before backfilling with drainage. Next to existing foundations, excavation is done in short lengths so the foundation is not undermined.
Methods and Limits
- Bitumen membranes. Torch-on or self-adhesive sheets on the outside face.
- Liquid membranes. Applied in coats, useful around complex shapes.
- Cementitious tanking. Applied to the inside or outside of the wall.
- Crystalline systems. React with concrete to block water paths.
- Cavity drain membranes. Let water in behind a membrane and drain it to a sump.
- Damp-proof course injection. For rising damp in walls above ground.
Waterproofing keeps moisture out. It does not repair cracks, settlement or other structural movement. Add subsoil drainage where groundwater is the source.
Process
- Enquiry. Photos and a description of the damp.
- Inspection. Finds whether the moisture is rising, penetrating or from a leak.
- System choice. Membrane, tanking or injection, with drainage if needed.
- Quote. Priced per m² or per metre of wall.
- Installation. Excavation, preparation, application, protection and backfill.
Foundation Waterproofing Prices
Ballpark prices so you can sanity-check a quote. They are not quotations and no contractor is bound by them.
| Item | Ballpark price |
|---|---|
| Below-grade damp-proofing | R180 - R350 per m² |
| Cementitious tanking | R380 - R650 per m² |
| Crystalline system | R450 - R800 per m² |
| Bentonite membrane | R550 - R950 per m² |
| Cavity drain membrane with sump | R600 - R1,100 per m² |
| Foundation waterproofing | R350 - R850 per metre |
| Rising damp, chemical DPC injection | R450 - R1,500 per metre |
| Basement: full exterior excavation and tanking | R40,000 - R80,000 per job |
Ballpark figures, not quotations. Ranges compiled from price guides and rate lists published by South African building-cost and contractor websites, checked 16 October 2026 and rounded. They are not our prices and no contractor is bound by them. Some sources quote excluding VAT. Most sources do not say whether VAT is included, so confirm VAT on every quote.
Sources:
- The Handyman Johannesburg, foundation construction costs (updated February 2026)
- Waterproofing Cape Town, waterproofing prices 2026 (August 2026)
- Completo, waterproofing costs (updated May 2026)
- ServiceLinkSA, waterproofing costs in South Africa (updated March 2026)
What affects the price
- Area and depth of wall
- Excavation and access
- Waterproofing system
- Surface repairs before application
- Drainage and sumps
- Backfill, paving and interior finishes
Get prices for your actual job rather than a range. Free, with no obligation to appoint anyone.
Compare Waterproofing QuotesProperty Types
Houses with below-ground rooms or split levels, basements, retaining walls, apartment blocks and commercial buildings.
Related Services
Compare specialists through Foundation Repairs South Africa: one free request, quotes from independent contractors.
Frequently Asked Questions
Will waterproofing fix foundation cracks?
No. Waterproofing keeps moisture out. Cracks and movement need a structural assessment and repair.
Is outside or inside waterproofing better?
Outside stops water before it reaches the wall but needs excavation. Inside systems manage water where outside access is not possible.
What is tanking?
A continuous waterproof layer, often cementitious, applied to below-ground walls and floors.
Is rising damp the same as foundation waterproofing?
No. Rising damp is moisture drawn up through walls above ground, usually treated with a damp-proof course. Foundation waterproofing deals with walls below ground.
Does excavation next to my foundation risk damage?
It can if done carelessly. Work is done in short sections so the foundation stays supported.
Foundation Repairs South Africa is a free quote-comparison service. Work is assessed, quoted and carried out by independent contractors and specialists, and your agreement is with the one you appoint. Ask each for a written quote, what is and is not included, who designs and signs off the work, proof of insurance and the payment terms before paying anything.
Foundation Waterproofing South Africa. Describe the job once and compare quotes.
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