A 30-year handshake deal on shutdown overtime just beat the fine print
A nearly 30-year understanding between a cement manufacturer and its union has survived a challenge from the employer.
New Zealand's Employment Relations Authority ruled on October 5, 2026 that Golden Bay Cement - a division of Fletcher Concrete and Infrastructure - could not compel shift workers to work overtime during planned maintenance shutdowns. The Authority declined the company's application outright.
The fight was over a single question: does the collective agreement give the employer the right to direct production shift workers onto shutdown overtime rosters?
Golden Bay Cement said yes. The union said not a chance.
The collective agreement pays workers under what is called a stable income plan - an annualised salary covering a set number of hours, with an overtime component built in. The employer argued that because workers are compensated for overtime availability, they can be directed to work those hours whenever the business needs them. Shutdowns included.
But the way it had actually worked, for nearly three decades, told a different story.
Since 1996, when the stable income plan was first introduced, shift workers at the company's Portland Plant in Whangarei had never been required to work overtime during the twice-yearly maintenance shutdowns. Shutdown overtime was volunteered for. It was allocated by reference to skill, availability, and personal circumstances. Both sides operated on that basis without issue.
Then, in April 2024, the employer flagged a change. It told the union it wanted shift workers required to work shutdown overtime, citing operational pressures - skill mix challenges, labour shortages, and the need to make better use of available overtime hours. The parties attended mediation twice. They could not agree. The issue also sat on the table in current bargaining for a new collective agreement.
The union pushed back hard. It argued the employer was attempting a "sharp interpretation" of the collective agreement to override how it had actually been applied for decades. It pointed out there were no concrete examples of production being curtailed, customers being affected, or operations failing because of the existing arrangement.
The Authority sided with the union.
Its reasoning came down to this: the collective agreement does not exist in a vacuum. The overtime clauses say work must be "shared equally" between worker classifications and that overtime may be required in "certain circumstances" - but neither term is defined. Over 30 years, the parties filled those gaps themselves. They developed practical arrangements - what the Authority called "shorthand" - to manage overtime within the broader framework. For shift workers, that shorthand meant volunteering for shutdown overtime.
If one party is no longer comfortable with that shorthand, the Authority found, the answer is not to reach for a strict reading of a single clause. The more complex mechanisms within the collective agreement need to be engaged to work out what those open-ended terms actually mean in context.
The employer's preferred interpretation of the stable income plan clause did not do that work. The application was declined. Costs were left to lie where they fell.
For HR teams running on long-term collective agreements, the case puts it plainly: how an agreement has been lived for decades can carry as much weight as what it says on paper. A dormant clause does not spring back to life just because the employer decides it is convenient.
