Offices in a timber mill were destroyed in an overnight blaze but firefighters managed to save stacks of processed timber ready for export.

Fire crews from Ruakaka, Waipu, Portland, three appliances from Whangarei and an operational support team rushed to ETC 2006 Ltd on Port Marsden Rd in Ruakaka about 1.20am yesterday.

Another appliance from the New Zealand Refinery was dispatched but wasn't required.

Ruakaka Fire Brigade station officer Jeff D'Ath said the office building was totally involved when firefighters arrived and the fire had spread on to the pallets of timber ready for export.


His brigade could not assemble together a second crew so help was sought from nearby brigades.

"We had to make some choices and try to save the stacks of timber ... that was our priority since the office building was totally involved when we got there," Mr D'Ath said.

With the help of other brigades, the crews fought for hours and managed to save most of the timber pellets.

Mr D'Ath said their work became tough at times with LPG and other flammable liquid kept on premises.

"Our concern was lots of timber on site but we managed to save them plus a shipping container that was in the storage area."

Fire investigator Craig Bain said the firefighters did a good job in saving the pallets of export timber. It was too early to say what caused the blaze: "It started in the office and spread into the staff smoker room and the workshop shed ... the building is completely destroyed."