Crews from Preston were called out to a domestic garage in Bushell Place at around 1pm on May 11.
The fire spread to the roof timbers and crews were forced to cut away parts of the roof to prevent the fire from spreading to the rest of the garage.
Watch Manager Mark Woodward said: "A workman had been repairing the roof when unfortunately there was an accident with his blowtorch.
"When we arrived the workman was trying to put the fire out with buckets of water. We got the man down to safety and spent around 30 mins fighting the fire.
"We used one hose-reel but the fire had spread to the timbers in the roof and we had to cut some of these away.
"Thankfully we managed to stop the fire from spreading further."
Nobody was injured during the fire.