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Q. What is a JJI-Joist?

A. A JJI-Joist is a structurally engineered timber joist, combining high-grade softwood flanges with an engineered composite panel web. For more information please see our Product Range.

Q. How do I obtain JJI-Joists?

A. James Jones & Sons do not sell JJI-Joists direct. JJI-Joists are sold through a network of distributors, who will provide a design and quote based on a full set of architectural drawings. For a full list of distributors, please see How & Where to Buy.

Q. Can I use JJI-Joists in a ground floor construction?

A. JJI-Joists can be used in the ground floor construction of a residential dwelling. Various factors, however, must be taken into account. For more information on the design of ground floors using JJI-Joists, consult JJI-Joist Technical Bulletin 9 (Revision B) - Ground Floor Design and Restraint.

Q. Can JJI-Joists be used in the construction of roofs?

A. JJI-Joists can be used in the design of both flat and pitched roofs. JoistMaster V3 allows the user to design flat and pitched roofs.

Q. Can I cut or notch the flanges of JJI-Joists?

A. Under no circumstances must the flanges of joists be cut or notched. Should a flange become damaged, please consult JJI-Joist Technical Bulletin 43 for information regarding a remedial detail.

Q. Can I create holes in the web of JJI-Joists?

A. Holes for services can be created in the web of JJI-Joists. Please follow the Circular and Rectangular hole installation guides as printed in the JJI-Joist Technical Manual (Third Edition). Please see also JJI-Joist Technical Bulletin 7, entitled 'Holes in the Web of JJI-Joists'.

Q. Can I connect JJI-Joists to a steel beam?

A.Yes. Please see JJI-Joist Technical Bulletin 25 (Revision A) entitled 'JJI-Joist to Steel Beam Connection'.

Q. What Fire Protection do JJI-Joists offer?

A. JJI-Joists offer a variety of methods of achieving both 30 minute and 60 minute fire protection. Fire tests were carried out by Chiltern International Fire. The certificates can be downloaded from our Downloads section after registering for an account.

Q. I am a timber frame kit manufacturer and would like to buy direct and design my own JJI-Joists. What should I do?

A. Contact

Q. Is it possible to obtain separate 'E' and 'I' values for JJI-Joists?

A. This is not possible, due to a JJI-Joist being a composite material. Separate 'E' and 'I' values are only obtainable from a single material.

Q. Do JJI-Joists require preservative treatment?

A. This depends on the application. Normally JJI-Joists do not require preservative treatment. However, for more information on the preservative treatment of JJI-Joists please consult JJI-Joist Technical Bulletin 31 - JJI-Joist Treatment, or contact

Q. My question is not listed. Where can I get more information?

A. Contact James Jones & Sons, Timber Systems Division, at our Forres address, or email for more information.

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