Published: 08:42, 19 June 2009
More than 20 firefighters tackled a blaze that broke out at Dover Grammar School for Boys on Wednesday.
The fire started in the chemical lab just after 6pm.
Teachers still on the premises raised the alarm when they smelt burning.
Fire appliances from Dover, Whitfield and St Margaret's attended and were able to prevent the flames from spreading to the roof.
Damage was confined to the chemistry lab, which is on the first floor. Smoke damage affected nearby classrooms.
The blaze appeared to involved papers in the chemistry lab and fire investigators are trying to establish the cause.