The men were using the torch to repair a bitumen roof covering on a property in Somerset Place, behind Bambola’s in the Parade, when the timber decking caught alight and spread to the roof void.
By the time the Fire and Rescue Service attended at about 4 pm, the fire had spread to a bathroom below.
Using breathing apparatus and a high pressure hose reel jet, fire fighters managed to contain the fire to the flat roof and bathroom.
Noone is thought to have been hurt in the blaze which at its height was being tackled by 15 firefighters.
The Fire Service say that investigations into the fire concluded that it was caused by roofers who were making repairs to the flat roof.
