Before anyone water-blasts or sands an older roof
WorkSafe says a home built before 1 January 2000 may contain asbestos, and you can't tell by looking. Corrugated cement sheet (often called Super Six) and decramastic tiles from before the early 1980s are the usual suspects. Businesses must not use high-pressure water over 350 kPa on asbestos, so a roof like that gets tested before any prep. Resene adds that roofs installed before 1971 should be tested for lead. Our asbestos checker is a quick first step.
Is your roof worth painting?
Paint is a coating. It keeps the weather off roofing that's still doing its job, and it's the part of a roof you expect to renew.
Good candidates: longrun or corrugated iron that's faded or chalky with only surface rust, galvanised iron starting to weather, concrete tiles that have lost their colour, and textured metal tiles shedding stone chip.
Poor candidates: iron with holes or flaking rust along the laps, tiles cracking right across the roof, and anything that might be asbestos cement. Resene's roofing guide says a badly corroded roof is often better replaced, in full or sheet by sheet, than painted. Our guide to repaint or re-roof helps with that call.
Metal or tile: how the job differs
| Iron, longrun and COLORSTEEL | Concrete and clay tiles | |
|---|---|---|
| Why people paint | To protect the steel and keep the roof going | Mostly for looks. Resene says there's no other reason to paint concrete tiles |
| The prep that matters | Washing off salt and grime, treating red rust, priming bare or new metal | Killing moss, cleaning without cracking tiles, sealing porous concrete |
| What the makers say | NZ Steel's warranty won't cover paint added to COLORSTEEL later | Monier says repainting concrete tiles doesn't improve waterproofing |
| More detail | Painting an iron roof | Painting a tile roof |
What happens on a roof painting job
Check what's there
The roofer confirms the roofing type, looks for rust, cracked tiles, loose fixings and tired flashings, and tests the old paint. Dulux's method is to cut an X through it, press tape over the cut and rip it off. If paint lifts, it comes off before recoating.
Repairs come first
Rusted screws, holed sheets, broken tiles and failed flashings are dealt with before any paint goes on. Resene points out that painting won't stop a leak if its source isn't repaired.
Wash and treat
Growth is killed and removed, and metal is washed. Resene warns windblown salt settles on roofs surprisingly far inland, and recommends a freshwater wash each day before painting.
Prime what needs it
Bare, new or rusty metal and porous concrete get the primer or sealer the paint maker specifies, applied promptly so dew can't lift the edges overnight.
Topcoats in the right weather
Dulux asks for two full coats on sound, previously painted surfaces and three on new ones. Resene Summit Roof isn't applied below 8°C, Dulux Roof & Trim not below 10°C, and rain, frost or dew on drying paint damages the film. A few weather days are normal.
Do you need a consent or an LBP for a repaint?
Usually neither. Schedule 1 of the Building Act lets you repair and maintain parts of a building without a building consent when a comparable product is used, and a repaint is maintenance. An LBP (Licensed Building Practitioner) is only required for restricted building work, which applies to work that needs a consent.
The work still has to meet the Building Code, and a scheduled heritage home may have district plan rules too.
Painting is days of work at height
WorkSafe treats roof restoration that runs over some days for painting, resealing or repair as long-duration work, where scaffolding or edge protection should be considered. It also says single-storey homes need the same fall protection as two-storey ones. If one quote includes edge protection and another doesn't, you're not comparing the same job.
Once you've a feel for what your roof needs, a short description is all it takes for us to pass the job to one checked roofer near you.
What a good roof painting quote spells out
- The paint system by maker and product name, including the primer or sealer, and the colour
- How many coats, matched to the paint maker's data sheet for your surface
- How the roof will be cleaned and treated, and where the runoff goes
- Repairs listed item by item, separate from the painting
- Edge protection or scaffolding, and who provides it
- The paint maker's guarantee and what it asks of you, plus the roofer's workmanship terms
Your part, and the roofer's
You can
- Look over the roof from the ground or an upstairs window, and photograph faded, rusty or peeling patches
- Choose a colour from a real painted sample, seen against your house in daylight
- Tell the roofer about water tanks, solar panels and anything that mustn't catch overspray
Leave to a roofer
- Anything on the roof: washing, rust treatment and every coat
- Replacing screws, sheets, tiles or flashings
- Edge protection or scaffolding
- Arranging asbestos or lead testing on an older roof
What we'd do before booking a repaint
If the roofing is sound, we'd paint it while the old coating is merely tired, before bare patches and rust turn a repaint into a repair job. We'd want the quote to name the paint, the primer and the number of coats, with repairs listed separately. If the roofer finds rust through, tiles cracking all over or possible asbestos, we'd pause and weigh up a restoration or a re-roof first.
Want a roofer to take a look?
Tell us the job and your postcode. We match it with a Find My Roofer certified roofer who specialises in that kind of work, and they call you to quote. Your number goes to them alone.