Roof Slab Waterproofing: A SealPro Case Study
Roof Slab Maintenance & Waterproofing (ArmTec System) — installed as a complete SealPro system by BloemGuard.
A flat concrete roof slab only performs as well as the membrane bonded to it. Once that membrane ages, cracks and starts lifting from the substrate, water no longer needs a big opening to get in — a hairline joint is enough. The case study below shows how a failing slab system like this gets stripped back and properly reinstated with a seamless, reinforced waterproofing layer.
The problem
The existing waterproofing on the slab had delaminated and cracked with age. Sections of the old coating had pulled away from the concrete instead of moving with it, the joints were failing and beginning to separate from the substrate, and open cracks were tracking straight through to the structure below. The rainwater outlets hadn't been sealed correctly either, and years of dirt and weed growth had left them partially choked, so even the water that should have drained away was backing up on the slab instead. Left as is, every one of these faults was a direct route for water into the building, and a simple patch coat wasn't going to fix any of it — the slab needed a fully bonded, continuous system from edge to edge.
The solution
As an approved SealPro applicator, the contractor renewed the slab with the full ArmTec waterproofing system, built up in bonded layers for a durable, flexible finish:
- Prep and prime. The slab was cleaned back to a sound, sealable substrate, the blocked outlets were cleared out, and the concrete was primed with Penetrar to lock down the surface and guarantee adhesion for the layers to follow.
- Reinforce the weak points. Cracks, delaminated joints and outlet details were bridged with a Flex and StretchSeal membrane, so the movement zones in the slab can flex without tearing the new system.
- Embed the reinforced layer. HyperFlex was applied with ArmTec reinforcing mesh embedded through it, building a tough, monolithic membrane across the full field of the slab that carries load and resists cracking.
- Seal the surface. The system was finished with HydroSeal HF, a UV-stable topcoat that delivers one continuous, waterproof skin over the entire slab.
Every rainwater outlet and pipe penetration was re-sealed by hand, since these details are usually where a slab fails first.
The result
The slab now carries a single, seamless, fully bonded ArmTec membrane in place of the old patchwork of failing coatings. The cracks and lifted joints are gone, the outlets drain freely, and every pipe penetration is sealed tight. It's a flexible, hard-wearing waterproof system backed by a workmanship guarantee — built to handle summer storms for years to come.
If your slab roof is showing cracked coating, lifting joints, or outlets that never seem to drain properly, don't wait for the next storm to find the gap. BloemGuard is an approved SealPro applicator serving Bayswater and the greater Bloemfontein area, bringing the same proven ArmTec system to flat concrete roofs that need a lasting fix.
Contact BloemGuard for a free inspection and quote: 072 933 0162 · bloemguard.co.za
The work, step by step
