Corrugated iron is convenient for industrial roofs because it is durable, inexpensive, and easy to install. However, corrugated iron roofs are not without their problems, because leaks can occur around screw heads or along seams. Paint your corrugated iron roof with special rubberised roof paints to help seal the roof. Roof paints are also formulated to deflect heat, and will help the building stay cool on hot days.
Clean and prepare the roof to ensure proper adhesion of the paint. Use a wire brush to scrub away any loose rust or dirt. Use a rust converter to remove any rust stains. Wash the roof with a roof cleaner. Roof cleaner can be used with a power washer or placed in a garden hose bottle sprayer. Rinse and allow the roof to dry.
Paint the roof with roof primer. Make sure the primer is filling all seams and covering all screw heads. Use a primer from the same manufacturer as the paint to ensure compatibility. Primer and paint can be applied by brush, roller, or paint sprayer. Work in long strokes, going in the same direction as the corrugation. Start on one side of the roof, in a bottom corner. Work your way up, toward the ridge cap, and over, toward the other side of the roof. Allow the primer to dry according to the dry time indicated in the manufacturer instructions.
Paint the roof with roof paint in the same manner as the primer. Make sure the paint is also filling all seams and is covering all screw heads. Apply two to three coats for the best results.