The deal will strengthen Van Elle in the South East and bolster the piling fleet with 11 more piling rigs.
Van Elle will make an initial payment of £1.8m, and a deferred consideration payment of £2m subject to completion accounts, payable 12 months from completion.
Based in Leatherhead, Rock and Alluvium generated revenues of £15.5m in the year to June but dipped £200,000 into the red. Its assets stand at £3.7m and it employs around 60 staff.
Rock and Alluvium was established in 1963 and joined Galliford Try back in 1989. Since it has built a strong reputation primarily serving the residential and commercial sectors in London and the South East.
Van Elle has also entered into a five-year trading agreement with Galliford Try under which Van Elle will provide piling and geotechnical services . This should generate revenues in excess of £10m per annum alone.
The acquisition is expected to complete in mid-November 2023.
Mark Cutler, chief executive of Van Elle, said: “This deal accelerates our expansion into London and the South East, by bringing a highly-regarded business and team into the group with a proven track record, a strong order book and a well invested fleet.
“This follows the acquisition of ScrewFast Foundations in 2021.
“The Board has been very disciplined in reviewing acquisition opportunities in the intervening period to ensure they will support the delivery of our growth strategy. I believe that Rock and Alluvium will prove to be an excellent addition to the group.”