The company was installing a mezzanine floor at a factory in Sunbury-on-Thames, Surrey when the incident occurred on 13 January 2015. The contractor was working on the floor when he stepped backwards and fell through a hole where a lift was due to be installed.
Guildford Crown Court heard how the worker was hospitalised for two-months following the fall with a severe brain injury, which has meant he has been unable to work since the incident.
A Health and Safety Executive (HSE) investigation found that the company had failed to guard the hole in the floor plate or board it up preventing anyone from falling through on to the concrete floor.
M & L Installers pleaded guilty to a breach of the Work at Height Regulations, reg 6(3) and was served with a £20,000 fine and ordered to pay £9,165.56 costs.
Inspecting officer Amanda Huff said that the serious incident and devastation could have been avoided with basic safeguards. "The contractor's injuries were life-changing and he could have easily been killed," she said.