Mark Lambton, 50, from Darlington, was working for James Wilson, trading as J Wilson Home Improvements, when the incident happened in July 2011.
Wilson had secured work to replace roof tiles, point ridge tiles and fit a dry verge system to the gable end of a house in Wheeldale Close, Darlington. Lambton and a third man were hired to assist.
Darlington Magistrates’ Court heard that Lambton was on the roof clearing concrete debris and fell around six to seven metres while attempting to move onto a set of ladders at the gable end of the property.
He landed on the path at the side of the property.
He was rushed to hospital and was placed in a drug-induced coma for more than two months. He remains severely brain damaged, in a vegetative state with no likelihood of improvement.
James Wilson, trading as J Wilson Home Improvements, 53, of Darlington was fined £12,000 and ordered to pay £3,000 costs after pleading guilty to breaching safety breaches.
Speaking after the case, HSE Inspector Emma Scott, said: “The dangers of death and serious injury associated with falls from height during roof work are well known, and allowing such work to be carried out without any safety measures is totally unacceptable.
“This incident could have been easily avoided if appropriate edge protection and safe access had been put in place to prevent falls. Instead, Mr Lambton has suffered life-changing injuries that have left him in a vegetative state with no likelihood of improvement or recovery.”