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.

Yes you can, but keep the tubing away from the fixture and insulate the tubing in proximity of the fixture and follow manufacturers instructions.

open-web floor truss assembled through a unique process of finger joinery and waterproof structural adhesive instead of metal plates.

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 to Buy.

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 here.

OPEN JOIST is an engineered floor truss that takes advantage of the structural power of the triangle and the forces of compression and tension working together to create superior strength.

OPEN JOIST uses phenol resorcinol adhesive. This structural adhesive is the standard of the engineered wood products industry (also used by I-Joist and Glu-Lam manufacturers) and has been in use since the late 1940's. It is safe to say that the wood fiber in an OPEN JOIST floor truss would disintegrate from age before this glue would break down.

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.

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.

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 (Second Edition). Please see also JJI-Joist Technical Bulletin 7, entitled 'Holes in the Web of JJI-Joists'.

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

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 jji-joists@jamesjones.co.uk.

For the beams it is recommended to nail 2 – 2x6 boards together to make the beam and rest them on top of the post and attach with steel connectors. If the deck is going to be very low profile the beams can be mounted on the sides of the posts and attached with large bolts and/or brackets. For the joists 2x6 boards is all that is required. Spacing between the boards should follow building code and manufacturers guidelines (for composite decking).

Clear spans depend on truss spacing and floor loading requirements, but the maximum clear spans achievable (distance between bearings) with OPEN JOIST are:

Maximum Allowable Spans for #2 Douglas Fir-Larch1,2,3City of Medford and Jackson County Building Departments Roof, no ceiling; Low slope rafters=L/240; High slope rafters=L/180; Floors=L/360; Ceilings=L/240 (Drywall).

In order to use beam on top of joist, the deck must be at least 25" tall. Anything shorter than this and the software will switch to flush joist construction.

UnderDeck can be finished off as much as you like. Seamless gutters and downspouts are not necessary. However, most applications do utilize them.

x4 and 1x6 deck boards need to be installed on 16” centers. 5/4 x 4 and 5/4 x 6 deck boards need to be installed on 24” centers.

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.

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.