Siteserv, which provides fencing and scaffolding for major building projects, listed on Dublin's IEX and London's AIM markets today.
The shares launched at 55 cent each and the flotation raised €10.5m, valuing the firm at more than €50m.
The shareholders include its founder and chief executive Brian Harvey and Niall McFadden of Boundary Capital, and the offer was four times oversubscribed.
Mr Harvey told RTE radio the proceeds would be used to fund expansion through organic growth and acquisitions in Ireland and the UK.
