Metal Roof Waterproofing: A Case Study in IBR Sheeting Restoration

An older IBR steel roof had reached the point where its original coating could no longer protect the sheeting underneath. Years of sun exposure, seasonal rain and the constant expansion and contraction of the metal had worn the surface thin, and the first signs of trouble were already showing along the ribs and overlaps. Rather than a full re-sheet, the homeowner wanted the roof properly restored and sealed — a case that shows exactly why a structured waterproofing system beats a quick repaint.

The problem

IBR profile sheeting holds up well structurally, but its lifespan depends entirely on the condition of its coating and fixings. On this roof, the paint layer had chalked and faded, leaving bare metal exposed and rust starting to bloom along the raised ribs and side laps. The self-tapping screws had loosened slightly with years of thermal movement, and the sealant washers beneath them had perished — turning every screw line into a potential entry point for water. Left as-is, corrosion works its way under the coating and the joints keep opening further, so a full strip-back, treatment and re-seal was the only durable fix.

The solution

1. Access and prep. The roof was cleared and high-pressure washed and degreased back to a clean, sound surface, removing loose coating and surface contamination before any treatment began.
2. Rust treatment. Rusted sections were mechanically cleaned, treated with a rust converter, and primed to lock down the metal and give the coating system a stable, corrosion-free base.
3. Sealing the weak points. Every overlap, joint and screw line was reinforced with flexible seam-sealing compound and the fixings individually sealed, closing off the paths where water had been tracking through.
4. Waterproof membrane. A flexible waterproof membrane was applied over the prepared and sealed sheeting, forming a continuous layer that moves with the roof through heat and cold instead of cracking.
5. Finishing coats. Two coats of high-quality, UV-stable roof paint were applied for a uniform finish, and the gutters were cleaned and waterproofed to complete the drainage system.

The result

The roof reads as a single clean, uniform plane from ridge to eaves — sealed overlaps, protected screw lines and a fresh coating that will hold up against the elements for years. The rust has been stopped and encapsulated rather than just painted over, and every leak path identified during inspection has been closed. The outcome is a watertight, low-maintenance metal roof that won't need attention again for a long time.

This kind of remedial system — strip, treat, seal, membrane, finish — is standard practice for IBR and other metal roofing where full replacement isn't necessary but a simple repaint won't last. BloemGuard is an approved SealPro applicator serving Universitas and the greater Bloemfontein area, and this same process is used on every metal roof restoration undertaken in the region.

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

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