Weatherboards should be painted and finished in accordance with 'AS / NZS 2311:2000 – Guide to the Painting of Buildings'. Professional painters should have a copy of this standard and be familiar with it. In addition to the above standard, weatherboard manufacturers painting instructions should also be carefully followed. These instructions are normally indicated by a sticker placed on the back each weatherboard and are expanded on in individual company literature.
Weatherboards should be painted only when dry and when the board is near Equilibrium Moisture Content (EMC <16%). If there is doubt over the readiness of the board to be painted use a correctly calibrated moisture meter to measure board moisture content. Board size dimensions should also be checked. If the board is larger than its factory machined dimensions the board is likely to have taken on moisture and must be allowed to dry out. Failure to let the board return to factory machined sizes may result in shrinkage lap marks between the boards affecting overall aesthetics.
If there is any doubt over the condition of the weatherboard prior to painting contact the manufacturer.
Critical areas for painting include:
Preparation – Remove all loose material, dirt etc from the board surface. Spot prime exposed bare and damaged areas with premium oil based timber primer. If not already done, all nail holes should be filled with filler nominated as exterior type suitable for overcoating with acrylic paints. Lightly sand the surface where necessary to an even flat finish. If primer has been exposed to the weather for longer than six weeks you should consult your weatherboard manufacturer for additional painting advice.
Cut Ends – During installation seal all cut ends with an oil alkyd primer sealer. Jenkin End Seal, an aerosol spray that combines a treatment and primer is available. This easy to apply system seals the ends of all cut surfaces. The aerosol Jenkin end seal has also been BRANZ Appraised.
Priming – Jenkin A-lign is a dual coat system and offers time and labour savings in the painting process. No extra priming is required.
Final Coats – Two premium acrylic top coats of low gloss level should be applied to the boards. If following paint manufacturers instructions each coat should be applied at a minimum of 25 dry microns per coat. It is recommended that finished boards have a paint system total film build including primers that exceeds 100 dry microns. Good level paint film build offers superior weather protection, reduced maintenance, greater paint system longevity and aesthetic benefits.
Colour – Dark colours should be avoided. They absorb heat from the sun and increase the risk of board defects. For best performance select colours in a range of 45% Light Reflective Value (LRV) or greater, there are over 1,000 colour options available in this range, a selection of these are shown below.
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LRV:45 |
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LRV:54 |
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LRV:55 |
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LRV:63 |
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LRV:79 |
Maintenance
Routine maintenance is required as is regular washing of the exterior surface. Washing especially under eaves and overhangs helps remove marine salts and other contaminants that have a detrimental effect on the long term life of the coating and substrate. A gentle wash (not water blast) at least annually should be conducted.
When maintenance is required use premium primer and undercoats followed by the original topcoat. Paint system longevity depends largely on the environment and quality of the original paint system. A quality paint system should last in excess of 10 years.
Producer Statement Info
Builder will supply you with a quality assurance form:
Producer Statement Info