The A-Z of painting your house

Barbecues, picnics at the beach, games of cricket and painting the outside of the house or crib are as Kiwi as Buzzy Bee. It’s a lot of hard work but the satisfaction of seeing a shiny freshly painted house more than makes up for the toil.

The classic weatherboard bungalow probably requires the most maintenance of any style of house in New Zealand.

Trying to keep paint on timber, which is a dimensionally unstable material that expands and contracts with changing moisture content, can be a tough task.

You can think of the layer of paint on your house as being similar to the earth’s atmosphere; a great protective layer when it’s in good condition but when it breaks down, the thing it’s protecting will become dust in the wind.

Painting an average sized house may take weeks, so be prepared for a long campaign. A way of gleaning satisfaction throughout the job is to prepare and paint one wall at a time.

The first step on the road to resurrecting a decomposing weatherboard house is to get rid of mould, dirt, salt scale and the chalkiness. Water-blasting is one way of doing this.

When armed with a water blaster remember you’re not Rambo on a search-anddestroy mission. The stream of water is potentially destructive (never point it at anyone) so keep it moving, because if you stop in one place for too long you will gouge holes in the timber.

Also make sure you don’t blast at high pressure very close to the surfaces.

As waterblaster alternatives, there are a number of cleaning products manufactured by paint companies.

Water blasting is a good way of finding out if there is rot. If the blaster does uncover rot, don’t continue to play the water into the cavity.

Sometimes rotten areas are hard to detect, as they lie unseen under an undisturbed layer of paint.

Likely areas to check if you’re suspicious are the windowsills, the bottom rail of an opening sash and along the bottom edge of the weatherboard. Poke it with your putty knife and all will be revealed.

Small areas of rot can be fixed by digging the rot out, leaving it to dry and then covering the exposed timber with primer. Once the primer is dry, use a suitable filler to fill it.

These types of fillers dry by chemical reaction so be neat with your filling. If there is a large area of rot, the only way of fixing it is to replace the whole weatherboard, sill or window.

Once the water blasting is complete, scraping and sanding is the next big job. Start at the top and work downwards. A linbide scraper and 80 grit sandpaper is the best method for small areas.

Prime as you go, or dew or moisture will get under the feathered edge and lift it. Use an acrylic primer, making sure to dust off the area first. Thin the primer with a little water.

Scrape and sand the windows as you go, checking to see that the putty holding the glass in is in good condition.

Often, all it takes to get rid of old putty is to flick it out with a putty knife. Prime the empty rebate and replace the putty, smoothing it out using a putty knife. New linseed oil putty takes about 10 days for a skin to form before it is ready to paint. Using a synthetic putty for repairing rebates is a better idea; it can be painted within 24 hours.

The sharp edges of weatherboards and window sills need to be sanded to a slight rounded edge; this is called arrising.

Once everything is primed, you can go around with a caulking gun and fill any cracks where the soffit meets the fascia board and the weatherboards, down the side of the windows or where there are cracks that need an expandable filler. Now, it’s time to apply the top coats.

There are two schools of thought on whether or not to paint the windows first. Painting them first means the cutting in of the scribers is easier. (Scribers are the pieces of timber that run down the side of the windows and fill the gap between window and weatherboard). It does mean, though, that you have to be tidy doing the weatherboards or you’ll get drips on the windows.

Exterior window painting will be the most time consuming part of any painting project and can easily encompass up to 50 per cent of the time necessary to paint an entire home.

It can sometimes be quicker to take the opening sashes out and paint them separately on saw stools.

Paint the top and bottom of an opening sash with the same number of coats as the rest of the window. The top is susceptible to water sitting on top of it when open while the bottom can have water against it when closed with water pooling on the sill.

The better the brush, the better the finish and the easier it is to paint. For windows use 35-50mm bevelled cutting in brush. Don’t worry about getting a perfect line on the glass (overlap on to glass a couple of millimetres to get a good seal) when cutting in the putty, as it can be tidied up later with razor blade window cleaner.

The size of brush to use on weatherboards depends on the width of the board. You want a brush that will cover the whole width of the board but no more as you’ll end up repainting boards below and leaving thick areas.

The process of painting weatherboards is to do three boards at a time. Orientate the brush horizontally and do the bottom edges of the boards then the faces, using the brush vertically. If your boards are very wide then you could use a mini-roller.

If you find the idea of painting the whole house too intimidating, start with the fascia board and soffit on one wall, then tackle the windows, then the weatherboards.

If you focus on each single step, sweep of the sandpaper and brushstroke, the journey won’t be so overwhelming.