Roof Slab Waterproofing: A Bloemfontein Case Study
Flat concrete roof slab waterproofing (ArmTec system) — installed as a complete SealPro system by BloemGuard.
A flat concrete roof slab had started letting water through after years of sun, rain and thermal movement. The homeowner called in a specialist team after damp began showing on the ceiling below, and the crew set about restoring the slab with a fully bonded, seamless waterproofing system built for high-traffic flat roofs.
The problem: a cracked slab and water coming through the ceiling
Years of weathering had taken their toll on the exposed concrete. The surface was stained and worn, with hairline and structural cracks running across the slab — the classic path water follows once a coating has aged past its working life. Underneath, the damage had already reached the interior: watermarks and staining had spread across the ceiling, a clear sign the slab was no longer holding out the weather. Sitting close to living areas below, this roof needed a solution that could bridge movement, seal every detail and stand up to ongoing foot traffic.
The solution: a bonded ArmTec membrane system
As an approved SealPro applicator, the crew installed the ArmTec waterproofing system — a reinforced, monolithic membrane purpose-built for flat slabs like this one.
- Preparation and priming. The full slab was cleaned and prepared, then primed with Penetrar to lock down the concrete and create a sound bonding surface.
- Crack and detail reinforcement. Every crack, turn-up and outlet was strengthened with StretchSeal membrane bedded in Flex, sealing the exact points where water had been getting in.
- Reinforced membrane. HyperFlex was applied with ArmTec reinforcing mesh embedded through the field of the slab, building a tough, seamless membrane that bridges movement and ties the whole roof together.
- Waterproof topcoat. The system was finished with HydroSeal HF and a cementitious topcoat to seal, protect and give the slab a clean, hard-wearing surface.
Obstacles on the slab were worked around carefully, with fittings lifted and risers used where needed so the crew could waterproof cleanly beneath and around each one.
The result: a sealed, seamless roof ready for years of use
The finished slab is now a continuous, watertight surface that has closed off every crack and detail that was previously letting water in. The ceiling below is protected, and the roof is once again a clean, usable surface instead of a leak risk. Backed by a workmanship guarantee and genuine SealPro products, this kind of roof slab restoration is set for many dry seasons ahead.
BloemGuard is an approved SealPro applicator serving Bayswater and the greater Bloemfontein area. If your flat roof slab is showing cracks, staining or ceiling damp, don't wait for a small problem to become a structural one.
Contact BloemGuard for a free inspection and quote: 072 933 0162 · bloemguard.co.za
The work, step by step
