Stourton-based Sandwell Roofing Limited was also fined more than £41,000 after it failed to exercise control in ensuring the work carried out at the Norton Aluminium Factory, in Cannock, was safe.
Stephen Patrick Brennan, from Great Barr, fell through the roof at the factory in September 2015.
He was putting up scaffolding with his 56-year-old father, also called Stephen Brennan, when he fell 37ft.
Wolverhampton Crown Court heard a fire at the factory had caused extensive damage to the roof.
The factory appointed Sandwell Roofing Limited to carry out the repairs.
Stephen Brennan was then appointed as sub-contractor to install the scaffolding.
Prosecutor Mr Nigel Lawrence QC told the court that two risk assessments Brennan had submitted were “inadequate”.
Scaffolding was put up, but on a site visit it was noticed it didn’t extend as far as expected.
Safety nets were not installed.
Brennan was asked to return to extend the scaffolding, which he did on September 19 with sons Kieran and Stephen – when the fatal fall took place.
Brennan, of Lorimer Way, Pheasey, near Great Barr, had previously pleaded guilty to contravening section 2(1) of the Health and Safety at Work etc Act 1974, while Sandwell Roofing Limited admitted contravening section 3(1) of the same law.
Mr Lawrence said: “We have a situation where Sandwell Roofing Limited say Stephen Brennan was reckless and carried out work in an unsafe way – but Sandwell Roofing was supposed to be exercising some control.”
Defending Sandwell Roofing Limited, Mr Timothy Pole, said: “The company was not anticipating the roof was going to be accessed and they [Brennan] were explicitly told not do so.”
Mr Neil Fitzgibbon, defending Brennan, said: “His family life has been ripped apart by grief.”
Brennan was handed a six-month jail sentence, suspended for two years and ordered to carry out 180 hours of unpaid work.
He will also pay costs of £14,000.
Sandwell Roofing Limited was fined £41,125 and ordered to pay costs of £33,000 by Judge Barry Berlin.