Why have reddish brown stains appeared on the surface of my painted wall?

What is it?

These reddish brown stains are caused by the rusting of nails on the painted surface.

What are the possible causes?

  • Bleeding of rust to the top coat from non galvanised iron nails.
  • Rust from galvanised nail heads due to sanding and extreme weathering.

How can I fix this problem?

  • Before painting on a new surface which uses non galvanised nails, countersink the nailheads, and caulk with a high quality water based acrylic caulk.
  • Spot prime each nailhead and paint with a quality latex coating.
  • If you’re trying to fix existing nailhead rusting, wash off rust stains and sand the nailheads. Then, countersink, caulk and spot prime as above. Paint with a high quality latex coating.