Design efficiency is key to the success of the JJI-Joist system and we have developed a number of software design tools for this purpose. Our highly skilled and experienced sales and technical team complements these tools to allow us to offer some of the finest technical support in the industry.


As an engineered product, available in a wide range of section sizes, JJI-Joist layouts can be very structurally efficient when each joist is specifically designed for its particular loading and location. The correct selection of suitable, compatible metalwork can also make a big difference to the quality and cost of a JJI-Joist structure. Without the use of design software, this process tends to be laborious and time consuming. Fortunately for the designer, we have developed comprehensive, in-house, layout and engineering programmes to do the hard work for you.


JoistMaster can be used for quick initial sizing through to detailed analysis of complex load configurations.

JoistMaster is a single member design program that is available for free and is aimed at a wide range of user abilities from professional structural or civil engineers and architects, to students and individuals interested in self-build. JoistMaster produces detailed calculation output that is ideally formatted for submission to Building Control and other interested parties.

To request the link to download our JoistMaster software please email

FloorMaster and OptiMaster

FloorMaster and OptiMaster are for use by our national network of trained JJI-Joist distributors.

FloorMaster is a computer aided design program capable of producing fully detailed JJI-Joist layout drawings for use on site. FloorMaster is not available to the general public because of the level of training required, but by passing your design queries onto one of our distributors they can use it to quickly generate the best solution for your project. The output from FloorMaster can be exported to OptiMaster, our stock optimisation program, to allow the distributor to maximise their cutting efficiency and therefore offer the you the best possible solution.

BIM – Building Information modelling

The FloorMaster software used by our distributors is able to output the final, fully engineered layout to a three dimensional, data rich IFC file format that can be utilised in a full building model for projects, using the BIM approach.

Technical Support

Our experienced Technical Support Team provides cover for the whole of the UK, supporting our distributors, architects, engineers and end clients. Their detailed knowledge of our products and their end use, combined with a good understanding of modern construction processes and regulations, equips them well to provide you with the help you need to get your project done.

Design Office

The Timber Systems Design and Technical Office provides a central hub for high level engineering support, with seven experienced full-time designers and two engineers. As well as providing software, design and engineering advice, our Design Office prepares and maintains technical literature and develops new products and systems as part of the on-going R&D effort.

To contact our Technical Support Team and Design Office directly please visit our Contacts page.

JJI-Joist Technical Manual 5th edition Jan 21(6.91 MB)