Repair rust and paint steel roof edges or flashings

Guide to repairing rust and painting steel roof edges or flashings

Rust on steel roof edges and flashings must be cleaned back to stable metal before primer and coating. The repair order is simple: remove loose corrosion, treat rust where suitable, prime exposed steel and finish with a roof-suitable metal coating.

What do you need to repair rust and paint steel roof edges or flashings?

Cleaning and degreasing

Mipa silicone remover in liquid or spray format removes wax, grease and silicone so sanding, primer and topcoat work starts from a clean metal surface.

Rust stop treatment

Miparox anti-rust spray helps stabilise rusted areas after loose corrosion has been removed, so small steel roof-edge repairs can be prepared before primer and coating.

Epoxy primer system

Mipa EP 100-20 with Mipa EP 950-25 hardener and Mipa EP Thinner creates a zinc phosphate epoxy primer layer for steel, aluminium, zinc-coated metal and other demanding substrates.

Single-coat metal roof finish

Mipa VC 250-30 is a thixotropic satin matt single-layer coating for steel, zinc-coated steel, aluminium and PVC surfaces used on roofs, panels, pipes and exterior metal details.

Spray primer and topcoat repair

Mipa DS 4 in 1 Spray is a fast drying high-build acrylic spray for priming, corrosion protection and topcoat repair on steel, galvanized metal, aluminium, GRP, wood and common automotive plastics.

How to repair rust and paint steel roof edges or flashings

1
Clean and inspect

Clean the roof edge, flashing or steel trim, then inspect seams, screw areas, rust spots and edges before coating starts.
2
Remove loose rust and paint

Wire brush, scrape or sand until loose corrosion and peeling paint are gone and stable edges are feathered.
3
Treat rust and prime

Use rust treatment where suitable, then prime exposed steel or repaired areas with the epoxy primer system.
4
Coat the visible metal

Apply the selected metal coating by the method that gives the best coverage on the shape and access point.
5
Check water paths

Keep coating clear of drainage details, seal failures and moving joints that need repair before paint can protect properly.

Which roof edge repair products should you choose?

For rusty local areas

Choose Miparox anti-rust spray after loose rust has been removed and the area is ready for rust stabilisation.

For exposed steel repairs

Choose the EP primer system when sanding has opened bare steel or when the edge needs a stronger primer base before coating.

For the final visible finish

Choose VC 250-30 for prepared roof-edge metal, or DS 4 in 1 Spray for compact spray repairs and smaller flashing details.

Technical details

Mipa VC 250-30 is suitable for roofs, containers, pipes, doors and similar metal constructions made from steel, zinc-coated steel, aluminium and PVC.
Mipa EP 100-20 is a zinc phosphate epoxy primer for steel, zinc-coated steel, aluminium, fibreglass and mineral substrates.
Mipa DS 4 in 1 Spray combines corrosion protection, primer, topcoat and high-build technology in a fast drying acrylic spray format.
Miparox anti-rust spray is used after loose corrosion has been removed, not as a cover over flaky rust or failing paint.
Roof flashings must still shed water correctly after coating; failed joints and lifted metal need repair before painting.

Practical suggestion

Feather the edges around each rust repair. A sharp paint edge on a roof flashing can lift again faster than a properly blended repair area.