Remove Rust From A Garden Shed's Roof And Apply Sealer To The Treated Surface

If the edges of the metal roof on your garden shed have rusted, treat the corroded areas by completing the steps below. After finishing, apply a coat of rust-inhibiting sealer on the roof's surface to protect it from rusting again.


  • ladder
  • roofing detergent
  • water hose
  • bucket
  • scrub brush (with stiff bristles)
  • cordless nail puller
  • nail gun
  • roofing nails
  • hand sander
  • sandpaper (low grit)
  • naval jelly
  • foam brush
  • plastic sheeting
  • scissors
  • painter's tape
  • rust-inhibiting sealer
  • mixing stick
  • paint tray
  • paint roller, frame, and handle

Clean The Metal, Replace Hardware, And Remove Rust

Lean a ladder next to the side of the shed. Prepare a cleaning solution inside of a small bucket by mixing detergent that is designed for metal roofs with water. After applying the cleaning solution to dirty spots on the rooftop, use a scrub brush with stiff bristles to assist with loosening each stain. If any of the roofing nails have a rusted surface, use a cordless nail puller to remove them. Install new nails with a power nail gun.

Secure a piece of damp sandpaper to a hand sander. Move the sander back and forth over rust spots on the roof's surface. Grip the sander firmly as you press against the back of it. Use a foam brush to apply a coat of naval jelly to any thick sections of rust that are difficult to remove with the hand sander. After the jelly begins to disintegrate the rust spots, move a scrub brush back and forth over each spot. Rinse the rooftop off with a hose to eliminate small flecks of rust or naval jelly that remain. Wait for the metal surface to dry thoroughly.

Apply A Rust-Inhibiting Sealer

Cover portions of the shed that are adjacent to the rooftop with pieces of plastic sheeting. Use painter's tape to secure the edges of the sheeting. The sheeting will prevent sealer from getting onto the shed if the product accidentally spills. Mix a can of rust-inhibiting sealer that is formulated for exterior use, and add some of the sealer to a paint tray.

Use a paint roller to apply a thin, even coat of sealer across the roof's surface. Wait for the sealer to dry thoroughly and add a second coat of sealer to the roof in the same manner. After the second coat of sealer has dried, remove the strips of tape that are holding the pieces of plastic sheeting in place. 

For more information, contact local professionals like BCI Metal Roofing.