The attackers tried to destroy the road marking contractor’s fleet of vehicles and burn down the offices.
Arsonists set fire to vehicles in the storage yard containing propane gas cylinders.
But two brave employees on site at the time of the New Year’s day attack were able to drive several vehicles away to safety and prevent the fire reaching the buildings.
The company lost five trucks in the blaze but most of the fleet was saved and within a few days temporary replacements had been sourced with little disruption to the business.
New replacements will start arriving next month and the company said additional trucks are on order to meet a growing demand from clients.
Stephen Scott, Managing Director, said: “These arsonists knew that there were staff on site yet went ahead and endangered their lives in this attempt to put us out of business.
“We have offered a reward of £10,000 for information that leads to the conviction of those responsible.
“Anyone with information should contact Thames Valley Police or Crimestoppers.
“Obviously we have increased the level of security at our premises but otherwise it’s business as usual for our workforce of 75 who will continue to work on the contracts we have around the UK.”