"Gib's not an easy job. Everybody's wanting it at the moment and it's worth gold and I think we're worth gold because we deliver it and they can't get their Gib without us."
Driver assistant James Ramea has worked for CV Compton for a decade.
It felt like those delivering Gib had fallen off the value chain, he said.
"Their mark is 300 tonnes a day and if we exceed that then both companies, Winstone Wallboards and CV Compton, get a bonus and none of it gets shared out to the workers."
It took time to train workers to deliver the plasterboard but they often lasted less than a week on the job because it was heavy labour, Ramea said.
"It comes on pallets, the sizes ranging from 2.4 metres to 6 metres and the health and safety regulation that we go from is for a 30kg for single-man lift."
Fellow driver and union delegate Rick said he usually delivered three 10-tonne loads a day.
"We want to get paid what we're worth. We're worth more than this, but this is what we want for now."
First Union organiser Emreck Brown said CV Compton was paying its drivers below market rate at $26 an hour - when the benchmark was $30.
"I'm hoping the company will come and meet us at 11 per cent, just so that our members can live comfortably and get by week by week."
Gib was in demand and those delivering the plasterboard were working hard, he said.
"Prices of Gib has increased in the last couple of years and this year it has increased significantly. We need some support from the company just to help the members who're helping the company."
Ramea said some members were facing financial hardship but it was not something they liked to admit.
After rent and household expenses, he had little left in his pocket for food.
"A hundred dollars, that's got to go to food and your vehicle, it's pretty hard. You've got to depend on your other half or your family for support and no grown man wants to depend on their family. It's pretty embarrassing."
Union delegate and driver's assistant Wiki said: "Every bit counts for us, we all struggle and we need this. That's why we're here today."
The strike will continue until the end of the week unless an agreement is reached.
CV Compton has been approached for comment.