Exterior house painting

How an exterior repaint is done

The order matters more than the paint brand. Clean first, so paint sticks; scrape and sand back to a sound edge; fill and caulk gaps; prime anything bare; then lay two finish coats. Skipping any step shows up within a few seasons as peeling at board ends and sills.

1. Wash. A gentle wash removes dirt, salt and mould. No high-pressure blasting on weatherboards.
2. Scrape and sand. Loose paint comes off back to a firm edge. On older houses this is done wet to keep lead dust down.
3. Fill and caulk. Nail holes, cracks and gaps at trims are filled so water cannot get behind the paint.
4. Prime. Bare timber is primed the same day it is exposed where possible.
5. Finish coats. Usually two, laid on dry days and left to dry in between.

Weatherboard, plaster and brick

Each cladding takes a different system. Timber weatherboards need primer on bare wood and flexible acrylic finish coats. Solid plaster needs cracks filled and a sealer where it is chalky. Painted brick and block need a paint made for masonry. Fibre-cement may contain asbestos in older houses and is never sanded.

Villas and bungalows take longer than plain boards because of fretwork, sash windows and decades of old paint layers, and that shows in the price.

Lead-safe prep on older houses

Any house from the 1980s or earlier should be treated as having lead-based paint, as WorkSafe advises. That means wet scraping and sanding, drop sheets, collecting every chip, keeping kids and pets clear of the work area, and no open flame. It adds time, which a good quote shows as a line item.

• Dry sanding is not recommended unless the sander has dust extraction fitted.
• Water blasting is not used to remove old paint, and its waste water must never reach a drain.
• For your own reading, Health NZ explains who is most at risk from lead dust.

Drains, wash water and clean-up

Paint, wash water and paint chips should never get into a stormwater drain; those drains run directly to the harbour. Auckland Council’s guidance asks painters to cover drains, wash water-based brushes into a sewer-connected sink or onto the lawn, and never put solvents down any drain. Ask any painter how they will handle it.

Weather and timing

Exterior paint needs dry surfaces and a dry spell to cure. Spring is the busiest booking season in Auckland, and the drier months give the most painting days. Paint makers set minimum temperatures on their data sheets; dew in the morning and a cold evening can spoil a coat laid too late in the day.

A two-storey repaint may need scaffolding, which is planned and priced as part of the job.

Painting the outside of a house yourself

It can be done, and plenty of Aucklanders do it, but plan the job from the ground. A single-storey house with sound paint suits a careful amateur; a two-storey house, heavy flaking or an older house with lead paint is where most people hire. The prep order is the same either way, and so is the weather: dry surfaces, no rain due.

• Stay on the ground and use an extension pole for anything it can reach. WorkSafe treats ladders as a last resort for short, low tasks, and its working at height guidance applies at any height.
• Wash gently with a brush and hose. Never water blast weatherboards.
• Do the tape test, scrape back what lifts, and sand wet if the house is from the 1980s or earlier.
• Spot-prime bare timber the day it is exposed, then two finish coats, each one dry before the next.
• Keep wash water and paint out of the stormwater drains.

Auckland’s climate is hard on paint: high humidity slows drying, and UV exposure on north and west walls breaks paint down fastest. Paint each wall after the sun has moved off it, working round the house as the day goes.

Asked before a repaint

How long does it take to paint the outside of a house?

There is no fixed figure: the size of the house, the amount of prep and the weather set it. Washing and drying come first, and paint needs dry weather between coats, so a run of rain days stretches any job. A written quote should give an estimate in working days.

Should a house be water blasted before painting?

Not weatherboards. BRANZ says high-pressure water blasting should not be used on weatherboards because it forces water between the boards and into the timber. A gentle wash and scrub cleans the surface. Water blasting is also never used on material that may contain asbestos or on old lead paint.

How many coats of paint does an exterior need?

A sound repaint usually gets spot-priming on bare areas and two finish coats. Bare or heavily scraped timber needs a full primer, an undercoat and then the finish coats. One coat rarely gives an even, closed film on edges and board ends, which is where paint fails first.

What is the best weather for exterior painting?

Dry surfaces, no rain forecast while the paint cures, and mild temperatures. Paint makers set minimum temperatures and drying times on their data sheets, and a careful painter follows them. Early mornings with dew and late afternoons before a cold night are the times to avoid.