30 October 2023

THE ALUMASC GROUP PLC

('Alumasc' or 'the Group')

Acquisition of ARP Group - Update on CMA process

Further to the proposed acquisition of ARP Group announced on 25 July 2023, Alumasc confirms that the UK Competition and Markets Authority ('CMA') has today formally commenced its Phase 1 investigation into Alumasc's proposed acquisition of ARP Group. The statutory deadline for the CMA's decision is 22 December 2023.

Further updates will be provided in due course.

Enquiries:

The Alumasc Group plc +44 (0)1536 383844

Paul Hooper (Chief Executive)

Simon Dray (Group Finance Director)

Peel Hunt LLP (Broker) +44 (0)207 418 8831

Mike Bell

Ed Allsopp

Cavendish Capital Markets Ltd (Nominated Adviser) +44 (0)207 220 0561

Julian Blunt

Edward Whiley

Camarco (Financial PR)

Ginny Pulbrook +44 (0)203 757 4992

Rosie Driscoll +44 (0)203 757 4981

Email: alumasc@camarco.co.uk

Notes to Editors:

1 Alumasc is a UK-based supplier of premium sustainable building products, systems and solutions. Almost 80% of Group sales are driven by building regulations and specifications (architects and structural engineers) because of the performance characteristics offered.

2 The Group has three business segments with strong positions and brands in their individual markets. The three segments are: Water Management; Building Envelope; and Housebuilding Products.

3 The Group announced the proposed acquisition of ARP Group on 25 July 2023, subject to the CMA indicating that it has no further questions in relation to the acquisition, and that it does not intend to make a Phase 2 referral.