Our Timber Systems Division was launched over 20 years ago and has grown to become the UK’s largest manufacturer of FSC® and PEFC certified I-Joists, branded as JJI-Joists. Today JJI-Joists have a 45% share of the UK's I-Joist market and are used by every major UK housebuilder.

Our JJI-Joist system combines the JJI-Joist products with custom sized glued laminated timber (glulam) and system specific metalwork to create a highly flexible offering, ideal for framing structural floors, roofs and walls.

Like all James Jones' products, the JJI-Joist production process has been independently audited to PAS 2050 standard meaning we are able to provide accurate carbon negative numbers for those customers looking to measure the carbon footprint of their project.