Their concerns are cited in a Local Government Association report this week, which said that there were up to 1,800 school fires a year in the UK.
Three out of four fires were malicious, the report said, and a third of fires occurred during school hours.
The association estimated that school fires cost pound;115 million a year, disrupting the education of 90,000 children and - with the extended schools programme - the lives of entire communities.
Yet much of that money and upheaval could be saved if schools installed sprinklers, which are still regarded as too expensive by many education officials.
The association called for sprinklers to be made compulsory in all newly built school buildings.
Last month, a 12-year-old boy appeared in court in connection with a pound;2million arson attack that destroyed St Mary's RC Primary School in Middlesbrough.
Two other under-10s were also allegedly involved, but were too young to be charged by police.
Sue Lemmon, the headteacher, said the 30-year-old school buildings had not been fitted with sprinklers. "Schools just weren't built with sprinklers in those days," she said.
Her 18 staff and 185 pupils are now divided between two sites, with foundation pupils at a nearby school while the older pupils are taught in a church hall. They return to their repaired school next month.
The children had been upset, Mrs Lemmon said. "For some, their security is in school. Just little things, like knowing they will be served lunch on time. The fire took that security away."
As concern about school arson mounts, Dorset Fire and Rescue Service has run a week-long project with teenagers from local schools. The Sparc project equips youngsters with helmets and hoses and gets them to take part in fire drills aimed at teaching them about actions and consequences.
The association's* report said that the emotional impact of school fires on staff, pupils and the community often lasted years. But with the trauma came a degree of community support and solidarity.
The increasing trend for fires during the school day was regarded by the fire service as "a very worrying development", the report said.
One fire officer said: "It's only a matter of time before it will result in casualties."
Michael Murphy, chairman of the association's school fire prevention taskforce, said that as the extended schools programme rolled out, the effects of fires would become more costly and detrimental to society.
He said that there were misconceptions about the expense of installing sprinklers and that schools overestimated the likelihood of malfunctions and vandalism.
"Installing sprinklers in schools cuts insurance premiums dramatically, reduces the damage and cost of fires, reduces the social and economic costs of fire on local people, and protects the lives of children," he said.