Waterproofing Contractors in Johannesburg
Basement, roof, and exterior waterproofing solutions
Professional Waterproofing Services
Sinqobile Construction provides professional waterproofing and damp proofing services across Johannesburg and Gauteng. With 15+ years of experience, we have treated hundreds of properties suffering from roof leaks, rising damp, basement moisture, and bathroom waterproofing failures. Waterproofing in Johannesburg costs between R70 and R600 per square metre in 2026, depending on the method (torch-on membrane, bitumen spray, cementitious coating) and the area being treated. Gauteng's intense summer thunderstorms and highveld hail put enormous pressure on roofs, walls, and foundations — proper waterproofing is not a luxury, it is essential to protect your property investment. We diagnose the source of every damp or leak problem before recommending a solution, because treating the symptom without fixing the cause wastes money. All our waterproofing work includes a workmanship guarantee and uses products from established manufacturers (a.b.e., Sika, Dulux AquaShield).
Service Statistics
Pool Waterproofing Service
Our Waterproofing Services
Roof Waterproofing
Torch-on bitumen membrane, liquid-applied polyurethane, and acrylic coating systems for flat roofs, concrete roofs, and parapet walls. We prepare surfaces by cleaning, repairing cracks, and priming before applying waterproofing. Roof waterproofing costs R200–R500/m² depending on the system and roof condition.
Bathroom & Wet Area Waterproofing
Cementitious and liquid membrane waterproofing for shower floors, bath surrounds, and kitchen splash areas. Applied before tiling to prevent water penetration into the slab and walls below. Essential for preventing long-term structural damage and mould growth in your home.
Rising Damp Treatment
Chemical damp-proof course (DPC) injection to stop moisture wicking up through walls from the ground. We drill injection holes at 150 mm intervals along the affected wall, inject silicone-based damp-proofing cream, and replaster with salt-resistant render. Rising damp treatment costs R70–R250/m².
Basement & Below-Ground Waterproofing
Tanking systems for basements, cellars, and below-grade walls using bitumen membrane, cementitious slurry coatings, or cavity drain systems. Basement waterproofing is complex work requiring proper drainage design. Costs range from R800–R1,500/m² depending on the system and access conditions.
Exterior Wall Waterproofing
Clear water-repellent sealers and elastomeric coatings for face-brick, plaster, and concrete exterior walls. Prevents wind-driven rain from penetrating walls while allowing the substrate to breathe. Particularly important for west-facing walls in Johannesburg that bear the brunt of afternoon thunderstorms.
Waterproofing Cost Guide — Johannesburg 2026
Waterproofing costs depend on the method, surface area, and condition of the substrate. Roof waterproofing is generally more expensive than wall treatments due to material thickness and application complexity. All quotes include surface preparation, materials, labour, and workmanship guarantee.
| Service | Price Range |
|---|---|
| Torch-on membrane (flat roof) | R200 – R400 /m² |
| Bitumen spray-on waterproofing | R300 – R500 /m² |
| Rising damp injection (DPC) | R70 – R250 /m² |
| Internal damp proofing (tanking + render) | R320 – R650 /m² |
| Basement tanking system | R800 – R1,500 /m² |
| Bathroom waterproofing (before tiling) | R150 – R350 /m² |
| Exterior wall water-repellent sealer | R50 – R120 /m² |
| Damp-proof paint / coating | R300 – R450 /m² |
Our Waterproofing Process
We follow a proven process to ensure quality results every time
Damp & Leak Assessment
We inspect the affected area, use moisture meters to map the extent of the problem, and identify the water source — roof leak, rising damp, lateral penetration, or condensation.
Diagnosis & Quote
Based on the assessment, we recommend the most effective and cost-efficient waterproofing method. You receive an itemised quote with product specifications and guarantee terms.
Surface Prep & Application
We prepare the surface (clean, repair cracks, prime), then apply the waterproofing system according to manufacturer specifications. Multiple coats are applied where required with correct drying times between layers.
Testing & Guarantee
We flood-test flat roofs and bathrooms to verify the waterproofing is watertight. You receive a workmanship warranty and product specification sheets for your records.
Frequently Asked Questions — Waterproofing
How much does waterproofing cost in Johannesburg in 2026?
Waterproofing in Johannesburg costs between R70 and R600 per square metre in 2026, depending on the method and area. Rising damp treatment is the most affordable at R70–R250/m². Torch-on membrane for flat roofs costs R200–R400/m². Basement tanking is the most expensive at R800–R1,500/m². Bathroom waterproofing before tiling costs R150–R350/m². We provide free assessments and itemised quotes.
What causes rising damp in Johannesburg homes?
Rising damp occurs when ground moisture wicks up through walls via capillary action because the damp-proof course (DPC) has failed, was bridged during construction, or was never installed. It is common in older Johannesburg homes built before modern DPC standards. Signs include tide marks on internal walls, peeling paint at skirting level, salt deposits (efflorescence), and a musty smell. Chemical DPC injection is the standard treatment — it creates a new moisture barrier within the wall at a fraction of the cost of rebuilding.
How long does roof waterproofing last?
Quality torch-on bitumen membrane typically lasts 10–15 years. Liquid-applied polyurethane systems last 8–12 years. Acrylic coatings last 5–8 years but are easier and cheaper to reapply. The lifespan depends on the product quality, application thickness, surface preparation, and exposure to UV and hail. We use products from a.b.e., Sika, and Dulux AquaShield with proven track records in Gauteng conditions.
Should I waterproof my bathroom before tiling?
Yes — bathroom waterproofing before tiling is essential, not optional. Water penetrates through tile grout joints and if the substrate is not waterproofed, moisture will seep into the slab, causing structural damage, mould growth, and leaks to rooms below. We apply a cementitious or liquid membrane to the shower floor, walls (up to 1.8 m in the shower area), and any floor penetrations. This must cure fully before tiling begins. The cost is R150–R350/m² and prevents damage that would cost thousands to repair later.
Can you fix damp walls without removing plaster?
For rising damp, we inject chemical DPC through small holes drilled at the base of the wall — the existing plaster is then left to dry out over 4–8 weeks. However, if the plaster is severely salt-contaminated (white crystite deposits), it must be removed to 300 mm above the damp line and replaced with salt-resistant render. We assess the plaster condition during inspection and recommend the least invasive approach that will deliver a lasting result.
Related Services
Recent Waterproofing Projects
See examples of our quality waterproofing work
Pool Waterproofing Service
Professional pool waterproofing with quality sealants and expert application.
Ready for Your Waterproofing Project?
Contact Sinqobile Construction today for a free consultation and quote
Last updated: April 2026