Experts are continuing their campaign to get security systems fitted in more classrooms as new figures show the full cost of school arson jumped to Pounds 65 million in 2008.
Just 400 of the UK's 32,000 schools have sprinklers, despite government guidance that they should be installed in all those that are newly built.
Zurich Municipal, the main schools' insurer, says classroom fires are getting bigger and more expensive. Arson now features in 75 per cent of claims and the company wants sprinklers fitted in all new schools, including academies.
Rain and floods have played an important part in preventing school arsonists causing damage. A fall in claims in 2007 by about Pounds 20 million was credited to the wet weather. That summer saw many parts of the country severely flooded. Last year claims for fire damage rose again, and experts say use of sprinkler systems is the only viable solution.
Recent government figures, obtained by the Liberal Democrats, show that fires affect 20 schools every week.
Larry Stokes, underwriting manager at Zurich Municipal, said: "School fires continue to pose a significant threat, including to the newer academies, which are often built on the site of a school with previous experience of arson and other property-related damage.
"Government guidance stating schools built under the Building Schools for the Future programme are expected to install sprinkler systems was a huge step forward. But with progress on many of these dwindling or stalling altogether, there is a very real risk that we could start seeing the losses creep up to the higher levels of previous years.
"This would represent a missed opportunity to radically improve the fire resilience of schools that BSF represents."
He added: "We continue to advocate a mandatory sprinklers policy to best mitigate fire risk. Until such a time non-sprinklered schools must remain vigilant about fire risk. Recording any incident - no matter how small - can help mitigate future, more significant incidents."
Most school fires in the UK - 34 per cent - happen in London and the South East, followed by East Anglia (28 per cent), Wales and the South West (15 per cent), and the North East (11 per cent). The regions with fewest school fires are the Midlands (1 per cent), the North (2 per cent), the North West (6 per cent), and Scotland (3 per cent).
Each year more than 1,300 schools in the UK suffer fires large enough to be attended by local authority fire and rescue services. Fifty-six per cent of these were classed as non-accidental last year.
According to government estimates, the average cost of school fires in 2000-2004 was Pounds 58 million a year. Most happen in the winter months, according to figures for calls to firefighters.
A spokeswoman for the Department for Children, Schools and Families said: "We are working with the Arson Prevention Bureau to cut the number of arson attacks on schools, and local fire and rescue services also run schemes which target vandals or those showing an unhealthy interest in starting fires.
"Through Safer Schools Partnerships, which we plan to expand to all schools, the police and schools work together in dealing with issues of security and anti-social behaviour. The school's allocated police officer can make a powerful impression on pupils and foster a healthy respect for the law."
The DCSF has started to collect information on sprinklers in new schools. Schools get insurance discounts if they have sprinkler systems.
BLAZING A TRAIL
- Arsonists rarely carry combustible items, so store anything they could use away from the school, including litter bins.
- Closing doors at night will help to contain fire and smoke within the room of origin, or at the very least slow the fire's growth.
- Staff should be made aware of the potential for arson attacks during the school day; fire-risk assessments should reflect this.
- Fire safety lessons for pupils by the fire service should be held regularly.
- Fire drills should form part of the school's risk assessment; records should be kept.
- Tell children regularly that cigarette lighters and matches are not allowed in school.
- All fires, no matter how small, should be reported to the fire service. Arsonists often start with small attacks and police may be able to assess whether a school is at risk.