How to Paint a Metal Building

If the metal shed in the back yard is starting to look shabby, a new coat of paint could restore it to its initial luster and help prevent rust from corroding the walls. Though painting a metal building may seem like an ominous task, it isn't very different from painting a wood building. With some extra care in your prep work, painting will be easy and last for many years.

Step 1

Prepare your surface. Remove mildew by applying a mixture of 3 parts water to 1 part bleach. Remove loose paint or rust by scraping the affected areas with a wire brush. Finish by washing the whole building with soapy water or use a power washer with water. Let it completely dry.

Step 2

Apply two coats of primer with a paint sprayer or use brushes or rollers, following the manufacturer's directions on drying time. Use a primer suitable for metal. You only need to apply primer if the old paint comes off in a powdery form when wiped with your finger, or if the building has never been painted.

Step 3

Paint the building after the coats of primer are completely dry. Acrylic latex house paint suitable for painting on metal is recommended unless the previous coats of paint were oil-based. If the paint on the building was an oil-based paint, you must use oil-based primer and paint.