You’ve just spent a fortune on a new metal roof, hoping to end the days of living with buckets under the ceiling. Yet, after the first downpour, water still finds its way in.
Why? The answer usually isn't the quality of the material, but the competence of the installation crew. In construction, 80% of a roof's longevity depends on installation technique.
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Amateur workers often try to save material by making overlaps too short (less than 15-20cm). When heavy rain is accompanied by wind, water is forced backward into these gaps.
Over-tightening screws deforms the metal, while loose screws fail to seal the rubber washer. A rookie mistake is driving screws into the drainage channels instead of the ridges.
Handheld grinders generate heat that burns the galvanized coating and paint at the edges, leading to rapid corrosion and rust within months.
Areas like gutters, vents, and wall intersections require meticulous flashing and high-quality silicone. Inexperienced crews often apply silicone poorly, which shrinks and cracks under UV exposure.
If the slope is too low ($< 10\%$), water pools on the surface and eventually seeps through screw holes or joints.
