Flat Roof Waterproofing in South Africa keeps water draining off a flat roof and sealed out at every joint, upstand and outlet. Send one request and independent local waterproofing contractors reply with prices.
Say how big the flat roof is and where water stands or leaks, and get quotes.
Get Waterproofing QuotesDrainage Comes First
Most flat roof leaks start where water cannot get away.
- Falls. The roof must slope towards outlets, even if only slightly.
- Ponding. Water that stands for days breaks down membranes and finds joints.
- Outlets. Outlets need to be large enough, clear and properly sealed into the membrane.
- Overflows. Parapet roofs need overflows in case an outlet blocks.
Details That Leak
- Parapets. Cracked copings and tops of parapet walls let water behind the membrane.
- Upstands. The membrane must turn up walls and be finished under a flashing or chase.
- Penetrations. Pipes, vents, skylights and solar mounts each need their own seal.
- Expansion joints. Joints between slabs need a flexible detail, not a rigid patch.
Suitable Systems
- Torch on membrane. Common choice for flat concrete roofs and roofs with some ponding risk.
- Polyurethane liquid. Seamless and suits roofs with many penetrations.
- Acrylic system. Lighter option for well-draining flat roofs with little foot traffic.
- Screed to falls. Corrects drainage before the membrane goes on.
The system should follow an inspection of drainage and details. A new membrane on a roof that ponds will usually fail early.
Flat Roof Waterproofing Prices
Ballpark prices so you can sanity-check a quotation.
| Item | Ballpark price |
|---|---|
| Torch on membrane, 4mm | R250 - R450 per m² |
| Polyurethane liquid membrane | R350 - R500 per m² |
| Acrylic system | R120 - R280 per m² |
| Screed to falls | R60 - R150 per m² |
| Strip old membrane | R40 - R90 per m² |
| Outlet rework | R800 - R3,500 per outlet |
| 100 m² torch on roof with prep | R30,000 - R50,000 |
Prices JUST UPDATED. Indicative ballpark figures in rand, rounded, including labour unless stated. They are not our prices or quotations, and no contractor is bound by them. Confirm VAT, access costs, the product system and what each quotation includes.
Get prices for your property rather than a range. Send one request and see who replies.
Get Waterproofing QuotesWhat Affects the Quote
- Falls. Screeding to correct ponding adds material and drying time.
- Existing layers. Old membranes may need stripping before new work.
- Number of details. Each outlet, pipe and upstand adds labour.
- Finish. A walkable or reflective finish costs more than a basic coat.
How the Work Is Done
- Inspect. Check falls, outlets, parapets and the existing system.
- Strip and repair. Remove failed layers and repair cracks.
- Correct falls. Screed where water ponds, if needed.
- Details. Seal outlets, upstands and penetrations first.
- Membrane. Apply the main system with proper laps.
- Test. Check drainage with water or after the next rain.
Preparation and Disruption
- Dry weather. Most systems need a dry slab and a few dry days.
- Equipment. Air-conditioning units, solar panels and pot plants may need moving.
- Noise and smell. Torch on work involves gas burners and some smell.
- Access. Materials may be hoisted to the roof.
Maintenance and Questions to Ask
- Clear outlets. Keep outlets and gutters clear of leaves and debris.
- Inspect yearly. Check laps, upstands and copings before the rainy season.
- Ask. Will you fix the falls, how are outlets detailed, and what does the guarantee exclude?
Flat Roof Waterproofing FAQs
Should a flat roof have water standing on it?
Small puddles that dry within a day or two are common. Water that stands longer points to poor falls or blocked outlets.
Is torch on the best system for a flat roof?
It is a common choice, but liquid systems suit roofs with many penetrations. The contractor should recommend a system after checking drainage and details.
Can falls be fixed without breaking the roof?
Usually yes. A screed is laid over the slab to create a slope towards the outlets.
Can I walk on a waterproofed flat roof?
Some systems take light foot traffic, others need a walkway or protective finish. Ask before the system is chosen.
Related Services
Get flat roof quotes through Waterproofing South Africa and compare how each contractor will handle falls, outlets and upstands.
Waterproofing South Africa is a quote and referral service. We do not carry out waterproofing work and we do not employ contractors. Work is quoted and carried out by independent local contractors, and your agreement is with the one you choose. The right system depends on an inspection and the cause of the water ingress. Ask for a written quotation, the product system and the guarantee terms before you pay a deposit.
Flat Roof Waterproofing. Describe what you need once and get the best quote, fast.
Get Waterproofing QuotesGet the Best Quote, Fast
Keep it brief. Say what is leaking or damp, the type of surface and your suburb. Your enquiry is passed only to contractors suited to the job, and you decide whether to go ahead.
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