The Yorkshire firm, which also produces reuseable hoardings and fall protection systems, lifted group operating margin to 5.6% from 4.9%.
A clutch of major project wins late last year, helped to raise group revenue by a fifth to £47m generating a pre-tax profit in the six months to June up 38% to £2.68m.
The main structural steel business saw operating margin restored to 4.5%.
Mark Smith, chief executive of Billington, said: “We started the year with a record order book and consequently the first half has been a very busy period across all our businesses.
“We have continued to build our order book with further significant contracts secured.”
He said Billington had limited its exposure to the more troubled larger contractors and had been able to secure credit insurance on acceptable terms for all its significant projects.
Billington Structures picked up a brace of contracts worth £30m in June ensuring production volumes will remain at similar levels.
Smith added: “While the overall market continues to be uncertain, the outlook for Billington remains positive, particularly given the group’s ability to target a diverse range of projects insulating us, in part, from any temporary slowdowns in the market.
“I look forward to the remainder of the year and beyond with cautious optimism.”