Our JJI-Joists offer several advantages over traditional structural timber beams, these include longer lengths, a composition that resists shrinking and warping, an excellent strength to weight ratio, straight and uniform dimensions and, uniquely, our JJI-Joists are FSC® and PAS 2050 accredited.
The JJI-Joists produced by James Jones at our Forres plant have the largest standard range available in the UK and are available in depths from 195mm up to 400mm deep with four flange sizes to facilitate a high degree of design optimisation enabling you to put the right product in the right place.
To read more about how our JJI-Joist system works and to access all the technical information required to specify and work with JJI-Joists please read our Technical Manual as a page turner by clicking here.
The full range of JJI-Joists is shown in the table below:
Other sizes are available, please contact your sales representative for further information.
| Joist depth | A+ | B+ | C | D |
| 47mm | 63mm | 72mm | 97mm | |
| 195mm |  | |||
| 220mm | | | | |
| 235mm | | | | |
| 240mm | | | | |
| 245mm | | | | |
| 300mm | | | | |
| 350mm | | |||
| 400mm | | |||
Use our Interactive Span Table to quickly find out what size JJI-Joists you'll require for your project.
How To Buy
JJI-Joists are available through our network of UK distributors, for contact details of your nearest distributor visit our Distributor Map.
Our distributors can provide you with a full design and quotation service, along with information about delivery time scales. Quotations typically include all required structural timbers and associated metal work.
Alternatively, contact our Timber Systems Division team directly, individual contact details can be found in our Contacts section.
Main Tel: 01309 671 111
Email: jji-joists@jamesjones.co.uk
Durability and treatment
Standard product
JJI-Joists are untreated and when used in a Service Class 1 or 2 environment, the ETA certificate advises that they may be taken to have a service life in excess of 50 years.