Around 15 striking Bunnings staff are blocking customers trying to get into the store at New Lynn in Auckland.

They're protesting against new fortnightly rosters, which the First Union says are taking control of people's lives by chopping and changing their starting hours.

Bunnings says it's offering staff a pay increase which will take their basic hourly rate to 17 dollars 50.

But Bunnings staff outside the New Lynn store this lunchtime aren't happy. Some have chained themselves to the front of the branch.

First Union spokeswoman Maxine Gay says new fortnightly rosters give the company too much power over workers' lives.

She says what the company is trying to do is bribe people with a pay increase so workers will stop protesting against the roster system.

Police and store managers are trying to deal with the situation.