Travis Perkins, which also owns Wickes, Toolstation, Keyline and Tile Giant, has seen its share price increase by more than 50% over the past year.
Employees who have been members of the share scheme for five years could see profits of £50,000, if the share price remains at its current level.
Travis Perkins', HR director, Carol Kavanagh, said the scheme was a great way for its employees to share in the group's success.
"Employees who've contributed £250 a month into our 2008 five-year scheme now have a total investment worth more than £62,000 (at today's share price), which is a great way to save for the future and certainly delivers a very nice windfall," she said.
The scheme was launched in 2002 to offer a risk-free three or five year savings option to employees.