Accounts for last year reveal the firm lost £12m adding to the £8.5m it lost in 2017.
Revenue at the Harrow-based building services contractor fell back 22% to £109m.
Vice chairman PM Matthew said that legacy projects were now completed and the firm does not foresee further problem jobs this year.
He said: “The board remain confident in the company’s prospects for 2019, having entered the year with a backlog of contracted work and a promising pipeline of opportunities which are being vigorously pursued.
“The company continues to streamline its internal processes and control, building on projects delivered in the last year to reduce direct cost and overheads, to improve the company’s competitive position in the market.
“The financial position of the business, its cash flows, liquidity position and borrowing facilities have been been reviewed and are deemed satisfactory.”
He added that the group’s Jersey registered paraent company had provided Lorne Stewart with an undertaking that it would continue to make funds available as needed.