A faulty water-based cedar stain was applied to some new Hobsonville Point house exteriors, resulting in peeling and mould and sparking residents' complaints about the suddenness of appearance changes.
Bruce McKinnon, chief executive of Jalcon Homes which has built many places in the upmarket north-western precinct, said the bad stain was applied to some cedar-clad houses.
"There was found to be a fault in the stain which resulted in some stain peeling and or mould appearing under the stain," McKinnon said.
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The effects differed on different areas of the affected houses and not all colours were affected in the same way, he said.
Jalcon is working with the stain manufacturer to fix the defects.
"We are trialling a solution prior to Christmas to prove its result and if successful we will complete the remedy at our cost to the other houses involved. Once remedied the owners will need to follow a regular maintenance programme of reapplication," McKinnon said.
A rich brown cedar tone on one house had turned a silver-grey within a short time period. The only reason for asking about the issue was to seek neighbours' advice and the feedback received was "blown out of all proportion".
The owner stressed complete satisfaction with the house and said she loved living at Hobsonville Point.
But McKinnon said Jalcon understood concerns expressed by some residents and was doing all it could to get quick solutions and provide help.
Other Hobsonville Point houses where an oil-based stain was applied had shown the normal fading or silvering effects over time, he said.
Homeowners had a responsibility to undertake maintenance reapplication according to the sort of look they wanted for their places, he said.
Cedar had natural preservatives within the timber. Stains were only used to give a cosmetic finish to accentuate the appearance, he emphasised.
The weathering to a grey or silver was a normal process, he stressed, and should cause no concern. There were no watertightness issues with the places and "this is purely a cosmetic issue".
If owners were concerned, they should approach Jalcon, he said, stressing the big difference between the homes with the non-faulty oil-based stain and those with the faulty water-based stain.
"Owners who see their cedar silvering off and who know there have been some issues with water-based stains in the precinct can understandably easily confuse one and two," McKinnon said.
The Herald has previously reported on Hobsonville Point homeowner restrictions, whereby the residents cannot erect tents or gazebos in their front yards, paint their homes a different colour, must adhere to fence height, planting, deck building, paving and concrete work rules.
House alterations, lighting, external alarms, fireworks, rubbish, lawn mowing and tree trimming also carry restrictions.