Metal Roof Waterproofing: Treating Rust at the Source, Not Just Painting Over It
IBR roof sheeting maintenance, rust treatment, waterproofing and painting — installed as a complete SealPro system by BloemGuard.
IBR (corrugated metal) roofs are common on homes across Bloemfontein, and after a few years of sun, hail and summer storms without maintenance, what looks like a simple repaint job can turn out to be something much more serious. This case study covers a typical IBR roof rescue: a job that started as a routine coating and became a full rust-remediation and waterproofing project once the crew got up on the roof and saw the true condition of the sheeting.
The problem with the roof
From ground level, roofs like this one often look tired but manageable — a bit of fading, maybe some surface rust near the edges. Up close, the picture changes. Large sections of IBR sheeting can corrode down to a deep orange-brown, with the protective coating gone entirely in places and active rust breaking through the metal along the ribs and overlaps. The screw fixings and joint lines are usually the worst-affected areas, which is no accident — that's exactly where water finds its way in first. Valley and gutter-box junctions with failing old sealant let moisture track behind the brickwork, compounding the damage. Left untreated, active rust on a metal roof doesn't stay cosmetic. It eats through the sheeting and turns into leaks, ceiling damage and, eventually, structural replacement costs.
The solution
As an approved SealPro applicator, BloemGuard follows a proper rust-remediation sequence rather than simply rolling paint over the problem:
- High-pressure wash the full roof area to strip loose scale, chalking and surface contamination before any product touches the metal.
- Rust conversion on every corroded section, chemically neutralising the active rust so it can't keep spreading under the new coating.
- Waterproof the overlaps, joints and screw lines — the highest-risk points on any IBR roof — with a reinforced waterproofing system, embedding fibre mesh into the coating over each screw head and rib joint for a durable, flexible seal.
- Prime the prepared sections to give the topcoat proper adhesion and long-term rust resistance.
- Apply two coats of a high-quality roof paint system, giving the sheeting a uniform, weather-resistant finish that reflects heat and sheds water instead of trapping it.
- Paint the bargeboards, gutters and down pipes to match, finishing the roof and roof-edge detailing as one consistent system rather than a patched-together repair.
The result
The rusted sections of sheeting are 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 box 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.
BloemGuard is an approved SealPro applicator serving Bayswater and the greater Bloemfontein area.
Contact BloemGuard for a free inspection and quote: 072 933 0162 · bloemguard.co.za
The work, step by step
