Bridgend based Central Roofing (South Wales) Ltd has been ordered to pay compensation to factory owner Mueller Europe following a High Court hearing.
The blaze broke out in November 2008 at Mueller’s Bilston factory where Central was working on a major £2m roof refurbishment contract.
Central had rigged a suspended “birdcage” scaffold just below the roof.
The scaffold was boarded out and sheeted with combustible materials.
The ruling by Mr Justice Stuart-Smith stated: “The fire occurred because one or both of a pair of gas-powered radiant heaters operated and set light to the combustible materials in the scaffold.
“The heaters were part of the system for heating the factory and were suspended from the roof structure.
“The birdcage scaffold enclosed the heaters so that they were only a short distance above the upper surface of the scaffold’s floor.
“Once enclosed by the combustible materials of the completed birdcage scaffold, the heaters were an obvious fire hazard, which should have been appreciated by anyone who turned their mind to the question”
He ordered Central to pay Mueller a total of £21,357,889.