Roof Painting: Benefits, Prep and When to Repaint

Roof painting is one of the best ways to protect a tired roof and make a house look new again. A good paint system shields cement tiles and metal sheets from sun, rain and salty air. But the paint is only as good as the prep under it.

This guide explains the benefits, the steps a proper job should follow, and the signs that your roof is due.

We spray paint tiled, Harvey tile and zinc roofs across Cape Town and the Western Cape. Here is what we have learned about doing it right.

Why roof painting is worth it

A roof takes more punishment than any other part of the house. Summer sun bakes it. Winter fronts hit it with wind and rain.

Near the coast, salt in the air settles on it every day. Paint is the layer that takes that wear, so the tile or sheet does not.

Signs your roof needs painting

Stand across the road and look at your roof in good daylight. Then check from a ladder if it is safe. These are the signs we look for.

• The colour is patchy or much lighter than it was.
• You can rub a chalky powder off the surface with your finger.
• Old paint is peeling or flaking in sheets.
• Moss, lichen or black mould grows on the shaded side.
• Metal sheets show rust spots at the overlaps, screws or edges.
• Tiles look rough and soak up water quickly after rain.

Roof painting prep: the part that makes it last

Most roof paint failures are prep failures. Paint put over dirt, moss, loose material or rust will lift within a few seasons. A proper job follows these steps in order.

1. 1
   Inspect the whole roof
   Check every tile, sheet, ridge cap, flashing and valley. Note broken tiles, loose screws and cracked mortar.
2. 2
   Do the repairs
   Replace cracked tiles, re-bed loose ridge caps, change rusted screws and fix flashings. This is normal roof repairs work and must happen before any paint.
3. 3
   High pressure clean
   Wash off dirt, moss, lichen and loose paint. Proper high pressure cleaning removes most of it with water alone.
4. 4
   Treat growth and rust
   Kill any remaining moss or mould. On metal, treat rust spots and use a suitable metal primer.
5. 5
   Let it dry fully
   The roof must be completely dry. Damp tiles trap water under the paint and cause blisters.
6. 6
   Prime where needed
   Cement tiles and bare metal usually need a primer or sealer so the topcoat grips well.
7. 7
   Spray two topcoats
   We use the spray method for an even coat that gets into tile edges. Two coats give better cover and life than one thick coat.

Which roofs can be painted?

Different roofs need different paint systems. Using the wrong product is a common reason for early peeling.

Roof sealing vs roof painting vs waterproofing

These words get mixed up, so here is the simple version. Roof painting is the colour coat that protects the surface. Roof sealing usually means a sealer or primer under the paint, plus sealing gaps at ridges, screws and flashings.

Waterproofing is a different job. It means a membrane or system that stops water getting through, often on flat roofs, parapet walls or problem joints. If your roof has leak points, ask about roof waterproofing for those areas as part of the same job.

What drives the roof painting price

We do not quote a price per roof without seeing it, because every roof is different. These are the things that move the cost up or down.

• Size and pitch. A steep or large roof takes longer and needs more paint.
• Height and access. Double storey homes need more safety set-up.
• Repairs needed. Broken tiles, ridges and rusted sheets add time and materials.
• Cleaning and treatment. Heavy moss or old flaking paint takes longer to remove.
• Paint system. Primer type, number of coats and paint quality all affect cost and life.

A cheap quote often skips the repairs or the primer. Ask each contractor to list every step. Then you can compare like with like.

For general guidance on paint quality, the South African Paint Manufacturing Association (SAPMA) is a useful source.

Best season for roof painting in Cape Town

Cape Town gets most of its rain in winter. So the best window is usually from late spring to early autumn, when roofs dry fast. But summer brings the south-easter, and strong wind is bad for spray painting.

We plan around calm, dry days and check the forecast for each coat.

If you want your roof done before the winter rains, book in late summer. That leaves time for repairs if the inspection finds problems. You can get a free quote any time of year.

Mistakes to avoid

• Painting over moss or dirt to save a day.
• Skipping repairs and hoping the paint will seal cracks.
• Using wall paint on a roof. Roof paint is made to flex and handle heat.
• Painting when rain is forecast within a few hours.
• One thick coat instead of two proper coats.
• Forgetting gutters, flashings and fascias, which then look old next to the new roof.

Roof painting: questions we get asked