A British Columbia weigh scale expert is at the Whitehorse landfill today examining the extent of damage from the fire which destroyed the gatehouse early Tuesday morning.

Dave Muir, the city's manager of public works, said some precision components in the scale were melted by the fire, which has been ruled arson by the territorial fire marshall's office.

"If we have to replace the weigh scale, that could be up around $100,000, and repairs could up around $25,000,” Muir said in an interview today.

"We should know today whether there has been any structural damage to the degree we need to replace it.”

He said there's no question at least some of the components will have to be replaced because of heat damage.

The gatehouse which sat beside the scales at the entrance to the landfill was engulfed in flames when the operator arrived for work at about 6:50 a.m. Tuesday.

Fire chief Clive Sparks said this week it had obviously been burning for a while by the time the gatehouse operator reported it because there wasn't much to be saved when firefighters arrived.

"At this point, we know it was deliberately set,” Yukon fire marshall Dennis Berry said Thursday. "We have ruled out other sources of ignition, like whether it was an electrical fire.”

The dump gate at the Alaska Highway had also been busted open.

Berry said his office is continuing with the investigation, along with the RCMP and Whitehorse Fire Department.

Samples from the fire scene have been taken and are in the hands of the RCMP for analysis, he said.

Berry said the police will be handling the criminal side of the investigation.

"If anybody knows who did this, we sure would like to step forward.”

Deliberately-set fires, said Berry, put the lives of first responders at risk, whether they're responding to structural fires or the rash of nuisance fires that popped up around urban parks and fields last summer.

The fire marshall said every time a fire crew responds, there is the potential for danger. People who set fires don't know or understand what could come of their deed.

The landfill remains closed to the general public but open to commercial operators and contractors.

Muir said the foundation for the ATCO trailer the city has secured to serve as the gatehouse was being finished up Thursday, and the facility should reopen to the general public soon.

Because of the sensitivity of the weigh scale components, it's difficult to determine the extent of damage by looking at them, Muir explained.

"There is no doubt it received enough heat to do some damage,” he said. "I mean, this is pretty precision equipment, and they have to be precise, because you are charging people based on weight.”

Muir said the expert from B.C. arrived Thursday afternoon and did bring with him all the components that might have to be replaced.

The gatehouse and associated equipment are covered by the city's fire insurance.