Customade, established in 1980, makes aluminium windows, doors and conservatory roofs, and is best known for its Real, Atlas and Fineline aluminium brands.
Barnsley-based Polyframe makes PVCu windows and composite doors.
“This merger is the culmination of our strategy to become the UK’s largest trade fabricator of PVCu and aluminium windows and composite entry doors,” Polyframe management said in a statement.
Customade is the third acquisition by Polyframe since its management-led buyout in July 2016. It took over Stevenswood’s factory in Livingston in November 2016 (Stevenswood took Polyframe’s trade centres in exchange), and The Window Bureau Limited (WB Group) a month before.
The Customade deal was supported by specialist investment firm Cairngorm Capital Partners, which also backed the MBO last July.
Customade managing director John Lightowlers now becomes group managing director of the newly combined company, supported by Gareth Thomas in charge of sales.