Preparing the surface prior to painting your home will make or break the job. It’s a large area requiring a lot of labour and a poor result is almost always due to the paint failing to adhere to a dirty, wet or flaky surface.
Making sure the exterior is clean, dry, free from grease, oils and loose paint will give the primer and paint a good surface from which to bond.
Around the house
Establish what needs to be protected and moved out of the way before work begins. Chemical products, paint chips, paint splatters and other debris can leave behind a big clean-up job and damage to landscaping and appliances if not considered first.
Move everything that can be moved out of the way. Use tarps to cover appliances and furniture. Plastic sheeting and tarps are not breathable so use canvass drop sheets to protect plants.
Turn off the power and gas to all appliances. Remove light fittings, shutters and awnings and anything fixed to the walls such as house numbers. Use this opportunity to do fixes and cleaning.
Protecting doors and windows
Remove window screens, storm doors and storm windows. Caulk any gaps around windows and doors with a paintable exterior grade product and allow to dry.
Mask neatly around the rims with painters tape and cover glass with newspaper and the door with a plastic sheet. Use a small scraping tool to get in around the moulding.
Scraping and washing
The first step in the surface preparation is to remove loose paint. A high pressure washer uses water from your hose and increases the pressure as it leaves the wand to between 2200 to 3500 per square inch (psi). Too much pressure can damage the walls.
There is also a risk that the walls can be too wet meaning either more drying time before paint can be applied, or if too hasty, poor adhesion. For this job, use at lower pressure and finish with hand scraping and sanding when the wall is dry.
Paint scrapers, putty knives, heat guns, wire brushes and sandpaper can all be used for getting the loose, crumbling paint off to leave the smooth surface that is needed for a perfect finish. Start with the brush to remove the loosest paint, then use a scraper and putty knife to tackle tougher parts.
Look for the weak spot in the peeling paint, get under it with the putty knife and lift. Scrape the excess away, being careful on timber cladding not to gouge the wood.
A heat gun can be useful on more stubborn areas. Keep it moving to avoid excessive heat build-up and as the paint softens, scrape it away with a putty knife.
Once the remaining paint has good bond to the surface and any holes or cracks have been filled, sand the peeled patches. Starting with 80-grit grit sandpaper on a block or an orbital sander for larger areas, smooth in a feathering motion to minimise the hard edge at the seam of where the paint has been removed and where it remains.
Using the fan spray attachment set a high pressure washer to low pressure wash the house to remove all residue, working from the top down. If there are any areas of mould or mildew, dilute household bleach at a ratio of one part bleach to three parts water and apply to affected areas using a thick scouring pad.
Wear goggles, gloves and old clothing to protect from splashes. Repeat as necessary.
After suitable drying time, your walls are ready to paint….
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