Firefighter arsonist appeals jail term

A former Rural Fire Service volunteer who lit a string of fires before helping to put them out has walked from court, hours after he was sentenced to a minimum 12 months in jail.

Magistrate Michelle Goodwin on Monday sentenced 20-year-old Joshua Staples to 18 months' jail with a non-parole period of one year.

But the offender has been let out on bail while he waits for his appeal to be heard next month.

Moments after the sentence was handed down, Staples' father shook his head as his son was handcuffed and led from Sydney's Downing Centre Local Court.

His mother grinned and called out "You right mate?" to her boy.

The Badgerys Creek man was later released on bail.

He was convicted of deliberately starting multiple grass and bin fires at Bringelly, Badgerys Creek and Greendale in January 2011.

In several cases, Staples doubled back to help fellow RFS firefighters extinguish the blazes, the court heard.

His lawyer had pushed for a part-time or non-custodial sentence.

"The offences are out of character for him, he's unlikely to reoffend, and has positive prospects for rehabilitation," Michael Coroneos told the court.

Mr Coroneos said his client was barely 18 when he lit the fires.

"He was one month and 21 days over the cut-off mark," he said.

Ms Goodwin said a psychiatrist's report showed there were "no psychiatric issues apparent" but "the offender still maintains his innocence".

"It is therefore difficult to assess any prospects for rehabilitation," she said before handing down her sentence.

"I am firmly of the view that the only appropriate sentence ... will be a sentence of full-time custody."

Staples' grandmother Veletta Heron, who crucially told Staples' hearing that her grandson had broken down at her kitchen table and confessed to lighting the fires, was not in court to see him sentenced.

The appeal is set to be heard in the Downing Centre District Court on October 23.