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Paint your house like a pro

29 Jan 2015

A coat of paint on the outside walls of your home can make all the difference in the world. But it needs to be done right for lasting benefit. The colour you choose is important; so is the type of paint you use, because your outside walls, windows and doors are exposed to all kinds of weather conditions for years.

Surface preparation

Remove all moss and mould: Thoroughly clean down to remove all loosely adhered material. Treat areas of moss or mould infestation with Resene Moss & Mould Killer, correctly diluted with clean water.

Leave for up to 48 hours to achieve full kill. For heavy infestations further applications may be needed. Wash thoroughly with clean water to remove all residue.

Wash surfaces: Use Resene Timber and Deck Wash to wash the surface and remove dirt and other contaminants.

Sand timber surfaces: Always sand along the grain to remove minor imperfections and any loose surface fibres. Loose fibres can be assumed to be present if the timber is left exposed to the weather for more than one week. Remove dust.

Sharp edges on timber are very difficult to apply paint to, as paint tends to flow away from edges, leaving weak spots. For best results sand these sharp edges to a rounded profile.

All sanding dusts can be harmful and appropriate protection should be worn. In particular dust from old lead or chromate based paint can be harmful if inhaled or ingested. Seek expert advice if the presence of these materials is suspected.

End grains: Always coat end grains (i.e. underneath the doors) as this prevents moisture penetration into the timber surface which will eventually crack the paint film.

Moisture: Generally timber should not be coated when its moisture content is above 17%.

First coat

If the surface you are painting is already painted and in good condition, then you can go straight to topcoating. In most cases Resene Quick Dry is the recommended primer for maximum flexibility and durability. Resene Quick Dry must be used as the first coat on totara and matai to seal the naturally occurring antioxidants.

Ensure all nail holes, damaged or split timbers are filled with a suitable filler and applied in accordance with the manufacturer’s instructions. Spot prime filler when dry with Resene Quick Dry.

NB: If staining is evident after the application of Resene Quick Dry, apply a further coat of Resene Enamel Undercoat.

Topcoats

Waterborne paints are the most suitable for exterior applications as they are more durable and flexible than solventborne paints.

Apply either Resene Hi-Glo (gloss), Resene Sonyx 101 (semi-gloss) or Resene Lumbersider (low sheen) at approximately 12 square metres per litre. Follow label instructions at all times.

These products are all available in standard or Resene CoolColour variants. Resene CoolColours are designed to reflect more of the sun’s energy than a standard colour, reducing heat buildup in the coating and substrate and reducing heat transference inside.

Top tip:? Resene TimberLock is a multi functional timber treatment that improves the dimensional stability of the substrate, as well as improving its fungal, water and ultraviolet light resistance. Its use improves the durability of subsequently applied topcoats. It is especially recommended on cedar that is to be painted, as well as on old weathered timber.