Once a year. That's our standard advice for most Wellington homes, and it's what we'd do on our own houses.
Some homes need it more often and a few can go longer. It depends on where you live, how much sun the walls get and what the house is clad in. Here's how to work out the right timing for yours.
Why Wellington houses get dirty so fast
Wind
Wellington wind doesn't just make it hard to hang the washing out. It carries road grime, dust and salt and presses it into every ledge, sill and lap of weatherboard. Houses on exposed ridges and near busy roads get a grey film that builds up quicker than you'd think.
Salt
Near the coast, around Porirua Harbour, Plimmerton and the south coast, the windward side of a house gets a salty haze. Salt holds moisture, dulls paint and is hard on aluminium joinery and metal fixings.
Damp and shade
Our winters are damp and plenty of homes sit on hillsides that block the low winter sun. A wall that doesn't see sun from May to September stays wet, and mould and algae love it. Up the Hutt Valley, frosty mornings and foggy days keep walls damp for longer too.
Which sides go green first
The south side, nearly every time. It gets the least sun and dries the slowest. After that, look at:
- Walls behind trees, hedges or a neighbour's house
- Eaves and soffits, where black mould spots gather
- Under the spouting, especially if the gutters overflow
- Around window frames and sills
- The windward wall on coastal homes, for salt build-up
If the south side is green and the north side is fine, you're probably due. Don't wait until the whole house goes.
How often for your house?
| Your house | Suggested wash |
|---|---|
| Sunny, sheltered, inland | Once a year, or a bit longer if it still looks clean |
| Average Wellington suburb | Once a year |
| Close to the sea or very exposed | Once a year, maybe more |
| Heavy shade, bush or tall trees | Once a year, maybe more |
| About to paint or sell | Right before, whatever the timing |
These are rules of thumb. The house will tell you when it needs it.
Why it saves on painting
Mould, algae and salt break down paint over time. A wall covered in growth stays damp, and paint on a damp wall fails faster. Washing it off every year means the paint lasts longer before you have to repaint.
There's also the prep side. Any painter will tell you paint won't stick to a dirty or mouldy surface. If you do get the house painted, it'll need a proper pre-paint wash first. Keep it washed in the meantime and that prep is simpler.
A wash costs a fraction of a repaint. Stretching the time between repaints is where the real saving is.
Signs you're overdue
- Green or black patches on the walls
- Black spots under the eaves
- Cobwebs and grime in the corners of windows
- A chalky or dull look to the paint
- Salt haze on the windows and joinery
- Paint that looks tired even though it's not flaking
How we wash a Wellington house
We soft wash, which means low pressure and a cleaning solution that kills mould and algae at the roots. It's gentle on old weatherboards and tired paint, and safe on plaster. A water blaster on the walls can strip paint and push water behind the boards, which is the last thing a Wellington villa needs.
We protect windows and plants, apply the solution, let it work, spot-treat stubborn stains and rinse everything off. You can read about the method on our soft wash Wellington page.
Best time of year
Late spring and summer are the most popular, with longer days and drier weather. Getting it done in spring means the house looks good all summer, and it's perfect timing if you're painting.
That said, we wash all year round. The main thing we avoid is a howling wind, because spray drift and fast drying make for a poor job.
Book your annual wash
If the south wall's going green, now's a good time. Book a house wash in Wellington and we'll give you a free quote first. Add a gutter clean to sort out the streaks under the spouting at the same time.
Call us on 027 303 8398. We're open seven days, 7am to 7pm.
House washing questions
How often should I wash my house in Wellington?
Once a year for most homes. Coastal, exposed or very shaded houses may need it more often.
Can I just hose it down myself?
A hose rinses off loose dust, but it won't kill mould or shift salt and grime properly. The growth comes back fast.
Will washing damage my paint?
Not with a soft wash. Low pressure and the right solution clean the surface without lifting sound paint.
How long does a house wash take?
A small house takes a few hours. Large multi-storey homes can take most of a day.