Roof Slab Waterproofing in Johannesburg South
Location: Johannesburg South, Gauteng
Service: Roof Slab Waterproofing
This case study looks at a flat concrete roof slab where the original waterproofing had reached the end of its service life. Large sections of the coating had delaminated and cracked, and water was already tracking through to the ceiling below. The property owner called in SealAll Roof Contractors to strip the failed system back and rebuild a proper, watertight roof from the substrate up.
The problem: cracked, delaminated waterproofing
On inspection, the existing waterproofing was clearly failing. Large sections had lost adhesion to the slab, and hairline cracks had opened up along the expansion joints, widening enough to let water track straight through the concrete. The signs were visible in more than one place:
- Delaminated, cracked coating across the main slab, with staining where water had been sitting and evaporating through the surface
- Open, separating joints where the membrane had lost its bond
- A stained ceiling inside the property, marking exactly where water had found its way through from above
Left unattended, cracks like these only get worse with every summer storm and every cycle of heat and cooling on an exposed slab.
The SealAll solution
As an approved SealPro applicator, SealAll Roof Contractors specified a slab waterproofing system built specifically for flat concrete roofs like this one. The team worked through the following steps on site:
- Substrate preparation – Cleared and prepared the slab, removing all failed coating and loose material back to a sound surface.
- Priming – Primed the full slab area to lock down the concrete and give the new system a proper key.
- Crack and joint reinforcement – Bridged and strengthened every crack and delaminated joint with a reinforcing membrane, closing off the points where water had been getting in.
- Monolithic waterproof coating – Applied the waterproofing system across the entire slab as a continuous, seamless layer, working the coating up and around all roof detailing.
- Roof fixture reinstatement – Lifted and reinstalled roof-mounted fixtures so the new waterproofing ran unbroken beneath them, with no gaps left around the bases.
The result
The slab now carries a single, continuous waterproofing layer with no weak joints or cracked patches left exposed. Every corner, upstand and parapet detail was sealed as part of the same system, and roof fixtures were reinstated onto a fully waterproofed base rather than left sitting on old, failing coating. The property now has a roof slab that sheds water reliably, with the leak that was staining the ceiling below fully resolved.
Flat concrete slabs across the Vaal region face the same combination of thermal movement, UV exposure and seasonal rain that caused this damage, which is why regular slab inspections are worth building into any maintenance schedule.
SealAll Roof Contractors is an approved SealPro applicator serving Vereeniging, Johannesburg South and the greater Vaal region.
Related SealAll Roof Contractors services: concrete slab waterproofing · roof waterproofing · torch-on alternative waterproofing across the Vaal Triangle.
Contact SealAll Roof Contractors for a free inspection and quote: 072 694 9243 · roofcontractors.co.za
#RoofSlabWaterproofing #JohannesburgSouth #VaalRoofing #SealProApplicator
IBR Metal Roof Rust Treatment & Waterproofing in Johannesburg South
Location: Johannesburg South, Gauteng
Service: IBR Metal Roof Rust Treatment, Waterproofing & Painting
This case study looks at a residential property with a large IBR (corrugated metal) roof that had gone years without maintenance. What started out as a straightforward repaint turned into a full rust-treatment and waterproofing job once the crew got up on the roof and saw the true condition of the sheeting.
The problem with the roof
From ground level the roof looked tired but manageable. Up close it was a different story. Large sections of the IBR sheeting had corroded down to a deep orange-brown, with the protective coating gone in places and rust breaking through the metal along the ribs and overlaps. The screw fixings and joint lines were the worst-affected areas — exactly where water finds its way in first — and a few pipe penetrations and gutter-box junctions had failing old sealant letting moisture track behind the brickwork. Left untreated, active rust like this doesn’t stay cosmetic for long: it eats through the sheeting and turns into leaks and structural replacement costs.
The SealAll solution
SealAll Roof Contractors, an approved SealPro applicator, followed a proper rust-remediation sequence rather than just rolling paint over the problem:
- High-pressure wash – The full roof area was stripped of loose scale, chalking and surface contamination before any product touched the metal.
- Rust conversion – Every corroded section was treated to chemically neutralise the active rust so it couldn’t keep spreading under the new coating.
- Waterproofing the overlaps, joints and screw lines – The highest-risk points on any IBR roof were sealed with a reinforced waterproofing system, embedding fibre mesh into the coating over each screw head and rib joint for a durable, flexible seal.
- Priming – The prepared sections were primed to give the topcoat proper adhesion and long-term rust resistance.
- Two coats of a high-quality roof paint system – This gave the sheeting a uniform, weather-resistant finish that reflects heat and sheds water instead of trapping it.
- Painting the gutters, fascias and pipe penetrations to match – The roof-edge detailing was finished as one consistent system rather than a patched-together repair.
The result
The rusted sections of sheeting are now sealed and neutralised instead of actively corroding, every screw line and overlap on the roof has a waterproof barrier built into it, and the gutter and edge detailing are cleanly coated and weather-tight. It’s the difference between a roof that’s merely been painted over and one that’s actually been treated at the source of the problem — which is what keeps a maintenance repaint from needing to be redone again in two years.
Metal roofs across the greater Vaal region face the same combination of intense summer sun, hail and seasonal storms that caused this damage, which is why catching rust early with a proper conversion-and-waterproofing sequence is far cheaper than waiting for a full re-sheet.
SealAll Roof Contractors is an approved SealPro applicator serving Vereeniging, Johannesburg South and the greater Vaal region.
Related SealAll Roof Contractors services: roof waterproofing · roof coating and painting · roof maintenance across the Vaal Triangle.
Contact SealAll Roof Contractors for a free inspection and quote: 072 694 9243 · roofcontractors.co.za
#IBRRoofPainting #JohannesburgSouth #VaalRoofing #SealProApplicator
Tile Roof Ridge & Valley Waterproofing in Johannesburg South
Location: Johannesburg South, Gauteng
Service: Tile Roof Ridge & Valley Waterproofing
This case study looks at a commercial property with a large tiled roof spanning several interlocking hips and valleys. Over the years, the original waterproofing along the ridge lines and valley sections had worn thin, and a number of tiles had cracked at the joints. The property owner called in SealAll Roof Contractors to inspect the roof and renew the waterproofing on the sections that were letting water in.
The problem with the existing roof
The ridge caps and valley lines on a tiled roof carry the highest volume of water runoff and take the most thermal movement, so they’re usually the first areas to fail. On this roof, the waterproofing along several ridge and valley sections had gone patchy and worn away in places, leaving bare cement exposed to the weather. In some spots the tiles themselves had cracked at the joints, with algae and moss taking hold in the gaps — a sure sign that moisture was sitting in the crack instead of running off. Left unaddressed, these worn sections were the most likely points for water to track down into the roof structure below.
The SealAll solution
SealAll Roof Contractors, an approved SealPro applicator, worked through the affected sections methodically:
- Roof inspection – Every ridge line, valley and hip was walked and checked to map exactly which sections of the existing waterproofing had failed and needed renewal.
- Crack and joint repair – Cracked tiles and open joints were cleaned out and rebedded to restore a solid, even substrate before any coating went down.
- Ridge and valley waterproofing – The worn sections were primed and resealed with a SealPro waterproofing membrane, rebuilding a continuous, flexible waterproof layer along the roof’s most vulnerable lines.
- Colour-matched top coat – Repaired and resealed sections were finished in a matching terracotta tone so the renewed areas blend into the rest of the tile roof rather than standing out as visible patches.
- Final quality check – Each renewed section was inspected from the roof to confirm the new membrane was fully bonded and watertight before sign-off.
The result
The sections of ridge and valley that had been letting water through are now sealed with a continuous waterproof membrane, and the cracked tile joints have been rebedded and resealed rather than left to widen over time. With the worn areas renewed and colour-matched into the rest of the roof, the building has a uniform, watertight tile roof again — protecting the interior below without the cost of a full re-roof.
Tiled roofs across the Vaal region face the same combination of thermal movement, UV exposure and seasonal rain that caused this damage, which is why regular ridge and valley inspections are worth building into any maintenance schedule.
SealAll Roof Contractors is an approved SealPro applicator serving Vereeniging, Johannesburg South and the greater Vaal region.
Related SealAll Roof Contractors services: weatherproof roof tiles · roof waterproofing · roof coating and painting across the Vaal Triangle.
Contact SealAll Roof Contractors for a free inspection and quote: 072 694 9243 · roofcontractors.co.za
#RoofWaterproofing #JohannesburgSouth #VaalRoofing #SealProApplicator
Roof Slab & Balcony Waterproofing in Johannesburg South
Location: Johannesburg South, Gauteng
Service: Roof Slab & Balcony Waterproofing
This case study looks at a modern double-storey home with several flat concrete roof slabs stepping down around the building, plus a large upstairs balcony. Together these flat surfaces added up to well over 300m² of bare concrete sitting directly under the sun, hail and summer downpours, with almost no margin for error if the waterproofing beneath them ever failed. SealAll Roof Contractors was brought in to get the slabs and balcony properly protected before any finish went down.
The problem: bare concrete with nowhere for water to go
Flat concrete roof slabs and balconies take more punishment than any pitched roof on a property. Left unprotected, bare concrete slowly cracks and turns porous, and water finds every hairline gap around outlets, upstands and parapet edges. What starts as a small damp patch on the ceiling below can end up as a structural repair. On this home, the roof slabs and the balcony both needed the substrate cleaned back, repaired and properly waterproofed before any finish could go down, and the balcony specifically needed a system that could still carry tiles on top without compromising the waterproofing underneath.
The SealAll solution
As an approved SealPro applicator, SealAll Roof Contractors treated the roof slabs and the balcony as two connected waterproofing projects, each built up in the same proven sequence:
- Substrate preparation and priming – Roughly 125m² of roof slab and 198m² of balcony were cleaned, repaired and primed to give the waterproofing system a sound, fully bonded base.
- Reinforced waterproofing membrane – A tough, flexible, seamless membrane was applied across both the roof slabs and the balcony, built to handle ponding water, foot traffic and UV exposure without cracking or lifting.
- Tile-ready topcoat on the balcony – Because the balcony was set to carry a tiled finish, it received a tile-ready topcoat over the waterproofing membrane, so the system stays protected and watertight once the final floor goes down.
- Quality control – Every section was checked for full, even coverage and correct falls to outlets before sign-off, working carefully around existing glazing, steelwork and fixtures already in place on site.
The result
The roof slabs and balcony on this home are now covered by a single, correctly specified waterproofing system instead of bare, exposed concrete. Water sheds properly off every flat surface, the balcony is ready for its tiled finish without putting the membrane beneath it at risk, and the property is protected against the cracking, ponding and leaks that untreated concrete slabs are prone to over time.
Flat concrete roofs and balconies across the Vaal region face the same combination of thermal movement, UV exposure and seasonal rain highlighted in this case study, which is why getting bare slabs waterproofed before cracks set in is always the cheaper option in the long run.
SealAll Roof Contractors is an approved SealPro applicator serving Vereeniging, Johannesburg South and the greater Vaal region.
Related SealAll Roof Contractors services: concrete slab waterproofing · roof waterproofing · torch-on alternative waterproofing across the Vaal Triangle.
Contact SealAll Roof Contractors for a free inspection and quote: 072 694 9243 · roofcontractors.co.za
#RoofSlabWaterproofing #JohannesburgSouth #VaalRoofing #SealProApplicator