Firefighters have activated a third alarm to help fight a "well involved" shed fire in the Rukuhia District south of Hamilton.
The shed, 40m by 40m, is half full of pool manufacturing equipment and half full of hay bales, a Fire and Emergency New Zealand spokeswoman said.
The fire was still fully ablaze at 8pm but the dark smoke clouds had slowed.
Five fire trucks were in attendance plus three water tankers.
Another two water tankers were en route to the scene.
Massive flames could be seen from the shed which is surrounded by a maize paddock.
The shed is not hear any residential or commercial properties.
Explosions could be heard coming from the burning building.
The fire is just a few hundred metres from Hamilton Airport
Lines of cars have queued up on Raynes Rd to watch the blaze and some people were standing on their cars to get a better look.
The scene caused many to stop driving to take a look. (Photo / Belinda Fleek)