The deal has yet to be approved by Siteserv’s shareholders. An EGM will be held later this month in Dublin where the firm is listed.
Siteserv chief executive Brian Harvey said: “The acquisition will provide Siteserv with a significant and immediate presence in the UK where Deborah Services is one of the market leaders.
“The acquisition is consistent with our stated strategy of continuing to grow by acquisition and particularly continuing to acquire businesses which are market leaders and which have strong management in place.”
Multi-discipline contractor Deborah was founded in 1967 specialises in the petro-chemical, power generation, civil engineering and building industries in the UK. It also has a scaffolding service and is one of the UK's largest providers in the hire and sale of non-mechanical plant and access equipment.
Founder Joe Whitlam named the firm after his daughter.