Roof Slab Waterproofing in Bryanston

Location: Bryanston, Johannesburg
Service: Roof slab maintenance and waterproofing (ArmTec HyperFlex System)

Flat concrete roof slabs give little warning before they start letting water in. The membrane looks intact from a distance, but underneath it the layers are delaminating, the joints are opening, and water that should be draining away is pooling instead. This case study follows a typical roof slab waterproofing project handled by an approved SealPro applicator: a slab where the existing system had reached the end of its life and needed to be stripped back and rebuilt from the substrate up. Across roughly 266 square metres of roof, the team returned it to a single, seamless, watertight surface.

The problem

The old waterproofing had failed in more than one way at once. The membrane had delaminated and cracked, with splits wide enough to slip a finger into, and the joints were separating instead of holding as one continuous skin. Water was standing in front of the outlets because they sat too high and the falls no longer drained correctly. Roof-mounted solar panels, their frame supports, and heating pipework all sat directly over the failing surface, adding obstacles that had to be carefully worked around.

The solution

Rather than patching the symptoms, the applicator followed a full remedial sequence using the ArmTec reinforced waterproofing system:

  1. Access. Disconnected and lifted the solar panels, frame supports and heating pipes to expose the full slab.
  2. Strip-out. Removed the delaminated old membrane and cleaned the substrate back to a sound, stable surface.
  3. Drainage correction. Opened the outlets to restore proper water flow, installing a new outlet where the existing falls could not be corrected.
  4. Priming. Applied Penetrar primer to key the coatings to the prepared concrete.
  5. Crack and joint bridging. Reinforced every crack and separating joint with Flex and StretchSeal membrane.
  6. Reinforced membrane. Installed the ArmTec system across the full slab, embedding reinforcing mesh into HyperFlex for a seamless, elastic layer.
  7. Topcoat. Finished with a HydroSeal HF topcoat for a durable, UV-stable waterproof surface.
  8. Reinstatement. Refitted the solar panels and frames, securing the solar structure back in place over the sound roof.

The result

The slab now reads as one continuous, seamless membrane, with no cracks, no lifted joints and no ponding water. Drainage runs cleanly to the corrected outlets, the solar array and pipework sit securely over a sound surface, and the structure below is protected against leaks for years to come.

Prime Seal Spray is an approved SealPro applicator serving Bryanston and the greater Johannesburg North area.

Related Prime Seal Spray services: roof waterproofing · waterproofing & painting across Johannesburg North · waterproofing & painting in Randburg.

Contact Prime Seal Spray for a free inspection and quote: 064 879 3553 · primesealspray.co.za

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