Eoin and Francis McCann were banned for 12 and 11 years respectively following an investigation by the cartel busting Competition and Markets Authority into price-fixing.
This saw three suppliers of concrete drainage products fined more than £36m for breaking competition law.
The CMA found that, from July 2006 to March 2013, FP McCann, Stanton Bonna Concrete and CPM Group agreed among themselves to fix or coordinate their prices, shared out the market by allocating customers and exchanged competitively sensitive information.
FP McCann appealed against the decision, but last December, the CMA’s determination was upheld by the Competition Appeal Tribunal.
At this time both directors resigned from the business.
The CMA said that reflecting the serious nature of the infringement and the directors’ involvement, it had secured the longest bans on directors holding office to date.
Michael Grenfell, executive director of Enforcement at the CMA, said: “The length of these disqualification periods reflects the seriousness of this case.
“The CMA will continue to take strong action, where necessary, to protect the public from illegal anticompetitive practices.
“The message to directors is clear – you are personally responsible for ensuring that your company complies with competition law, and if it doesn’t you risk disqualification.”
These disqualifications follow bans on Philip Stacey and Robert Smillie, who were previously directors of CPM, in April 2019.