From a modest plant hire and haulage firm founded in 1977 by Gerald and Valerie Harries, the business has grown into one of Wales’s largest suppliers of aggregates and a major civil engineering contractor. The company continues to uphold its family values, strong work ethic, and commitment to quality.
Despite significant expansion, the business remains proudly hands-on and community-focused, investing heavily in local employment, training, and suppliers.
FH Gilman & Co becomes a leading force in the Pembrokeshire quarrying industry. Begins ready‑mix concrete production and acquires Bolton Hill Quarry. Secures major early contracts, including work for local oil refineries, Llys y Fran, and key port facilities. Recognised as Pembrokeshire’s largest aggregates producer of the era. In November 2011, the Gilman business is acquired by GD Harries.
Gerald and Valerie Harries establish the company as a haulage and plant hire firm, laying the groundwork for what will become one of Wales’s most respected construction and quarrying businesses.
Tarmacadam becomes a significant part of GDH’s operations, supported by new plant investment at Blaencilgoed.
The company purchases its first quarry at Blaencilgoed — a pivotal moment in the business’s diversification. Investment in a new tar plant allows GDH to expand from one supply gang to four, serving customers across West Wales.
Significant developments continue at Blaencilgoed, strengthening the company’s production capabilities.
The Blaencilgoed Asphalt Plant opens in November. FH Gilman expands operations at Bolton Hill, shaping the quarrying activity still seen today.
GD Harries acquires the assets of FH Gilman, adding: 5 quarries 2 asphalt plants 2 concrete plants This major acquisition cements GDH as a regional leader in aggregates and construction materials.
Three new concrete plants open: Two in Carmarthenshire – Gelli Gaeros Trading Estate (Idole) and Penygroes One in Ceredigion – Allt Goch GDH also begins operations at Pembroke Dock Wharf, managing import and export of materials through the port until 2025.
Assets total approximately £26 million, including around 80 million tonnes of reserves and resources — enough for 100 years of quarrying.
SigmaRoc PLC completes its full acquisition of GD Harries. GDH becomes a cornerstone of SigmaRoc’s Welsh platform, accelerating growth, investment, and long-term sustainability.
Work begins on a new state-of-the-art asphalt facility in Llandarcy.
GD Harries officially opens the new Llandarcy Asphalt Plant—capable of producing 140 tonnes per hour, designed with sustainability, efficiency, and future infrastructure needs in mind.
Launch of the company’s rebrand as Cymru Quarry Group, marking an exciting evolution for the business and its future direction.
