Chadwicks Group, an Irish builders' merchant, stockpiled "several millions of euro" worth of products in advance of the two delayed Brexit deadlines.
In an interview with the Sunday Independent, Patrick Atkinson, CEO of Chadwicks Group, said the business underwent a scenario planning exercise for Brexit. For items that were identified as "critical", with a stock turn of a month, the company built up three months of supply to mitigate against tariffs and delays at the border.
Atkinson, who recently discussed the effect of Brexit on Chadwicks with Tánaiste Simon Coveney, said 75pc of his products were either distributed or manufactured by Irish companies.
"What we have done the last two times for Brexit is to put the correct products into our supply chain to ensure we have enough product for our customers," he said.
"We've done it a couple of times now, we've gotten better at it, but we don't want to do it again."
Atkinson said the company was less exposed to Brexit on Irish-produced products such as timber and plasterboard. He said exposed products included items such as glass wool insulation, which isn't made here, and could attract a tariff.