The group said profits growth was down to strong market growth and the inclusion of the first full year of trading for Metnor Galvanizing, which Hill & Smith acquired in November 2006.
Revenues increased by almost a third over the year, to £402 million from £306 million.
Chief executive Derek Muir said legislative changes had driven much of the market growth.
He said: "Government commitment to maintain and improve an ageing infrastructure, increasing legislation, health and safety and regulatory requirements, along with the effects of climate change, combine to offer exciting opportunities within global infrastructure markets.
"We will continue to develop our market presence and products to benefit from such opportunities."
In its preliminary annual results, the group also announced the appointment of a new group finance director Mark Pegler. This followed the retirement of Chris Burr.