Ben Edge, 25, was working without safety equipment in windy conditions in a quarry in Ramsbottom, Greater Manchester in 2014.
Christopher and Robert Brown, who admitted trying to cover up what had happened, were jailed for 20 months. Mark Aspin was sentenced to a year.
His mother Janet Edge blasted the men for their "abhorrent actions".
Speaking after the verdict, Mrs Edge said: "Ben was the most fun loving and hard-working man.
"He was like a breath of fresh air, always smiling with a huge friendly personality and would do anything for anyone.
"The sentence given to those responsible for Ben's death and for their abhorrent actions bears nothing compared to the life sentence that my family and I were given on the 10 December 2014.
"Nor does it do justice to an irreplaceable life."
Mr Edge fell from a structure he was helping to dismantle. He died from head injuries.
SR and RJ Brown Limited, of which brothers Christopher and Robert Brown are directors, was fined Â£300,000 at Manchester Crown Court after admitting corporate manslaughter.
Christopher Brown, 25, of Gollinrod Farm, Gollinrod, Bury, and Robert Brown, 32, of Lower Gollinrod Farm, near Ramsbottom, pleaded guilty to perverting the course of justice and two counts of health and safety breaches.
A count of manslaughter for the brothers is to lie on file.
Aspin, 37, of Hameldon Road, Hapton, Lancashire, was jailed after admitting health and safety offences.
The company he is director of - MA Excavations Ltd, of Garden Street, Ramsbottom, which contracted out the work - was fined Â£75,000 after pleading guilty to two health and safety breaches.
Employee Peter Heap, 34, of Copthurst Farm, Barrowford Road, Padiham, Burnley, was spared jail after he followed orders to bring safety harnesses to the site after his colleague had fallen to try to conceal what had happened.
His four-month sentence for perverting the course of justice, which he had admitted, was suspended for two years.
Three company bosses have been jailed following the death of a man who fell from a roof he was working on.