Metal Roof Waterproofing and Painting: A SealPro Case Study

This case study looks at a large corrugated metal roof that had reached the point where both its appearance and its protection were failing. The homeowner needed a contractor to strip back years of weathering, seal the vulnerable joints, and give the roof a durable, freshly painted finish able to handle harsh sun and seasonal storms.

The problem

The roof sheeting had faded to a patchy, chalky orange, and rust had taken hold across the panels. The worst damage was at the overlaps and screw lines, where old sealant had cracked and lifted and corrosion had eaten through in places, leaving open holes and blistered, discoloured metal. Left untreated, those failed joints and rusted fixings are exactly where water finds its way in. A separate low-pitch slab section also needed attention, with the old waterproofing worn thin and no longer sealing reliably.

The solution

Rather than simply painting over the problem, the job followed a full remedial SealPro system:

1. High-pressure clean and degrease of the entire roof to strip chalking, dirt and loose material back to a sound surface.
2. Rust treatment — corroded sections were wire-cleaned and treated with a rust converter to stop the corrosion spreading.
3. Prime the sheeting with Purple Prime to lock down the substrate and give the coating system something to grip.
4. Seal the joints and screw lines — weak points were reinforced with Flex and StretchSeal, and every fixing sealed with ScrewSeal so the overlaps and fasteners are fully watertight.
5. Waterproof the slab section using the ArmTec system — Penetrar primer, Flex and StretchSeal to the details, then HyperFlex with ArmTec reinforcing mesh and a HydroSeal HF top coat for a seamless membrane.
6. Paint the roof with two full coats of high-quality roof paint for a rich, even, UV-stable finish.

The result

The tired, rusted roof now reads as a clean, uniform finish from ridge to eaves, with the joints and screw lines properly sealed underneath rather than just hidden. The slab section is protected by a continuous ArmTec membrane, and the whole roof is set up to shrug off extreme weather for years to come — a cosmetic refresh and a genuine waterproofing upgrade in one project.

This type of remedial system is exactly what BloemGuard specialises in for metal roofs across the region. BloemGuard is an approved SealPro applicator serving Langenhoven Park and the greater Bloemfontein area.

Contact BloemGuard for a free inspection and quote: 072 933 0162 · bloemguard.co.za

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