Some house styles and wall claddings require less maintenance than others, but there is no such thing as a ‘maintenance-free house’.

All homeowners should inspect their homes regularly. To guide you in what you are looking for, refer to our Inspection checklist.

The maintenance you need to carry out on the exterior walls of your home will largely depend on the type of house you have – a 1905 weatherboard villa and a 1997 home with monolithic cladding and no eaves come with very different maintenance needs and risks, for example. Our maintenance guide on building periods can help here.

CLEANING

PAINTING

ASBESTOS WALL CLADDINGS

CLEANING

Almost all materials and finishes on the exterior walls will last longer if they are cleaned from time to time. Cleaning removes dust, dirt, mould, mosses, chemical residues and salt spray, all of which can hasten deterioration.

  • Wash down the exterior of the building yearly. 
  • Increase cleaning frequency to 3-monthly in geothermal or severe marine areas. 
  • Where unpainted steel cladding is used, wash down areas not rain-washed at 6-monthly intervals. 
  • Clean glass every 3–4 months, more frequently in severe marine areas.
  • Carry out cleaning with a low-pressure hose, a soft brush and a gentle detergent. Water-blasting might sound like a good idea, but it can lead to long-term damage if it forces water through gaps into the wall assembly.

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PAINTING

External paint coatings don’t last forever, and recoating must be carried out routinely to maintain decorative and weather-resistant properties. How long external paint will last depends on the:

  • quality of surface preparation and condition of the old paint. Paint will last better when the old paint is still in a reasonably sound condition and the surface is well prepared for the new paint
  • quality of the paint used. Typically, you get what you pay for – extremely cheap paints are likely to deteriorate faster than better quality (more expensive) paints
  • amount of sun shining on it – paint on the south side of a building gets less UV light exposure and will last longer than paint on the north or west side
  • colour – lighter colours tend to last longer than darker because they absorb less heat, so expand and contract less
  • size and type of material under the paint. Paint on wide timber boards won’t last as long as on narrow boards because the overall movement in wide boards is greater. Paint properly applied to cement-based materials (concrete, cement plaster, fibre-cement products) tends to last longer than paint on timber
  • cleanliness of the painted surface – wash down often to remove airborne chemicals and dirt from the surface
  • number of coats applied
  • underlying colour – applying a dark colour directly over a light one can cause a previously sound paint to lose adhesion because of the higher surface temperature.

Read our Painting guide for more information.

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ASBESTOS WALL CLADDINGS

BRANZ has estimated that around 9.5 million m2 of asbestos-cement wall claddings were installed on New Zealand homes in the period 1945–1984. If your home dates from this time and has the original cement-based sheet or plank cladding, the cladding may contain asbestos. If asbestos fibres get into the air and are breathed in they can cause potentially fatal illnesses. Fibre-cement wall claddings should never be water-blasted, sanded, cut with power saws or broken into pieces. Before removing a profiled cement-based wall cladding that is several decades old, get it tested to see whether it contains asbestos. You can find more information here.

 

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