Is roof painting worth it, or is it just cosmetic?

Roof restoration is the most aggressively marketed service in this trade, and the quality range is wider than in any other part of painting. It is worth separating what the coating genuinely does from what it is sold as doing.

Where it genuinely helps

**Concrete tiles.** This is the strongest case. Concrete roof tiles are manufactured with a coloured cement slurry on the surface, and that surface erodes. Once it has gone, the tile becomes porous — it absorbs water, gets heavier, grows lichen and moss, and sheds grit into the gutters. Recoating restores a sealed surface and genuinely extends the tile's service life.

**Colorbond and metal that has lost its coating.** The factory finish is excellent and finite. Once it has chalked through, the steel underneath is exposed to Perth's UV and, near the coast, salt. Repainting is real protection.

**Reducing heat load.** A lighter colour or a heat-reflective coating measurably reduces roof surface temperature and the heat entering the roof space. The effect on your power bill is real but modest and depends heavily on insulation.

Where it is cosmetic only

**Terracotta tiles.** Terracotta is a fired ceramic. It does not degrade the way concrete does — a hundred-year-old terracotta roof is often perfectly sound under the lichen. Coating it adds a maintenance liability to a material that did not have one, and once painted it must be repainted. Cleaning terracotta is usually the right answer.

**Roofs whose problem is not the surface.** Cracked tiles, failed pointing at the ridge caps, corroded valleys, perished flashings, blocked gutters. A coating does nothing for any of these, and a coating applied over them hides them.

The claims worth ignoring

**"It will fix your leak."** A coating is not waterproofing. Leaks come from failed flashings, cracked tiles, blocked valleys and perished ridge pointing. Fix those.

**"Fifteen-year warranty."** Read what it covers, who backs it, and what voids it. A warranty from an operator with no trading history is worth what it costs.

**"It will halve your power bill."** It will not. Heat-reflective coatings work, and ceiling insulation works far harder for less money.

**A price valid only today.** Roof restoration attracts high-pressure selling. A genuine quote is still genuine next week.

What a proper job involves

1. **Inspection and repair.** Replace broken tiles. Re-bed and re-point ridge caps where the mortar has failed. Check valleys, flashings and penetrations.
2. **High-pressure clean.** Remove lichen, moss, dirt and loose surface material. This is where most of the visual improvement comes from.
3. **Treat biological growth.** A fungicidal treatment so the lichen does not simply grow back through the new coating.
4. **Repair after cleaning.** Cleaning exposes defects the dirt was hiding, so a second look matters.
5. **Prime.** A sealer appropriate to the substrate — porous concrete tiles drink primer.
6. **Two coats** of a roof-grade membrane.

Steps one and four are the ones cut to make a price competitive, and they are the ones that decide whether the roof is actually better or just newer-looking.

The order of value

If you have a fixed budget and a tired roof, spend it in this order: repairs first, then gutter and valley cleaning, then insulation in the ceiling space, then coating. Coating a roof with failed pointing and no ceiling insulation is the least useful sequence and the one most often sold.

When it is clearly worth doing

A concrete tile roof, fifteen to twenty-five years old, with the surface slurry eroded, lichen growth and grit in the gutters, structurally sound and correctly repaired first. That roof will genuinely last longer coated, and it will look transformed.

That is a real and common case. It is just not every roof.