Grafton, the Dublin-based builders merchanting and DIY Group which owns Woodies, said it has completed the acquisition of Direct Builders Merchants in the UK.
The general merchanting business trades from three branches in Sittingbourne, Whitstable and Ashford in Kent.
"This bolt-on acquisition, which had revenue of £4.8m in the financial year to 31 December 2013, improves the group's coverage of the merchanting market in Kent and the south east of England," the company said in a brief statement.
Shares in Grafton extended recent gains, rising nine pence, or 1.4pc, to £6.54 in London.
The company generates 73pc of its group revenue in the UK and moved its stock market listing to London in 2013.
Grafton has operations in the UK, Ireland and Belgium.
The company has slowly expanded over the years by buying small builders' merchants to create a massive network in the UK and here.
The company said last week that profits surged 62pc to €63.6m in the first six months of the year as its UK and Irish businesses notched up strong performances.
Grafton's revenue in the period was 11pc higher at €1.27bn.
Speaking to the Irish Independent, chief executive Gavin Slark said that one of the "most encouraging" aspects of the performance in the first half was that its merchanting business in Ireland reported growth.
Grafton's Irish merchanting arm, which includes outlets such as Chadwicks and Heitons, reported revenue of €152.6m in the first six months of 2014, a 5.6pc rise on the first half of 2013. In euros, revenue was actually 9.4pc higher.
Operating profit at the unit jumped to £5.6m (€7m) from £1.5m.
"It's still very early doors for the recovery in Ireland," said Mr Slark, "but the recovery in Dublin is spreading out to cities such as Cork and Galway. The midlands remains quite tough."
He said the growth Grafton is seeing in Ireland is off "lots of small projects".