Metal & IBR roof coating
Purple Prime on every sheet, screwlines and laps reinforced, every screw head sealed with ScrewSeal — finished with HydroSeal HF and optional CoolRoof.
Metal roofs fail at their weak points long before the sheets themselves rust through: fasteners back out with thermal movement and their washers perish, side-lap seams open, and surface rust starts wherever the original coating was scratched or has chalked away. Bloemfontein's climate accelerates all three — big daily temperature swings work the fasteners, and hail bruises coatings open.
Painting over rust does not stop it; rust continues under the new coat and lifts it within a season. The correct sequence treats the corrosion chemically first, seals every seam and fastener as a detail, and only then applies the coating system.
For homes that run hot under sheet metal, the CoolRoof option reflects solar heat and measurably drops the temperature under the roof — a real difference in a Free State summer.
The SealPro systems we use
- Purple Prime — the metal roof primer and rust inhibitor that goes on every metal roof, no exceptions — IBR, corrugated iron, galvanised and Chromadek sheeting alike. Its purple colour confirms full, even coverage before anything else is applied.
- Flex + StretchSeal Membrane — flexible reinforcement embedded along every screwline, lap joint and overlap in a three-coat process.
- ScrewSeal patches — every individual screw head sealed with a 75mm fibreglass patch in three coats of Flex — all of them, not just the ones that leak.
- HydroSeal HF liquid rubber — two full coats forming a seamless rubberised waterproof membrane over the whole roof, with CoolRoof as an optional heat-reflective finish that drops under-roof temperatures.
How the job runs
- Inspect & quote — corrosion mapping, fastener and seam condition, gutter and flashing details.
- Prep & repair — mechanical cleaning of corroded areas, then Purple Prime over every sheet, full coverage.
- Seal & reinforce — Flex and StretchSeal along all screwlines and laps; ScrewSeal patches on every screw head.
- Topcoat & sign-off — two coats of HydroSeal HF, optional CoolRoof finish, walkthrough and documentation.
Common questions
My metal roof leaks but I cannot see any holes. Where is it coming in?
Almost always at fasteners and side-laps. Perished washers and opened seams let water in during driven rain, and it travels along the sheet profile before dripping. Sealing those details is the core of the job.
Does CoolRoof actually make a difference?
Yes — the bright-white reflective finish measurably reduces the heat load on the sheet and the space below it. On low-insulation roofs the difference on a summer afternoon is significant.
Can you coat over old rust if it is only surface deep?
Surface rust is mechanically cleaned and sealed under Purple Prime, which inhibits corrosion and bonds the system to the metal. Sheets rusted through at laps or fasteners are replaced first — coating cannot bridge a hole.