Overall group profit remained stable at £19m on revenue down 7% to £510m in the year to March 2018.
Most of the profits were generated by specialist concrete business P J Carey, which enjoyed a 5% operating margin.
Carey’s south east drylining business BDL also had a good year nearly doubling profit to £3.1m on revenue up a quarter to £86m.
John Carey, chairman of the group, said: “The past year generally has seen a strong performance for the group and where performance levels have fallen below expectations plans to drive improvements have been implemented.
“The board looks forward confidently to continuing growth and success of the business in 2018/19.”
Net assets grew over the year from £78m to £97m.
The group’s total retentions being held by clients amounted to £27m, up from £24m last year.