Spanning the timber industry

// the building envelope

Technical Editor Bruce Meechan talks to Jon Stevenson, Marketing Manager for James Jones, about the versatility of the company’s JJI-joists and its wider product offering.

I can still recall my first sight of James Jones’ sawmill operation in Scotland some ten years ago on a Wood-for-Good organized press trip: watching huge logs being spun at the top of a conveyor belt, ready to optimize the cut from each tree. In fact nothing is wasted with the products resulting from the process ranging from very large sections used mainly in agriculture, through construction timber, fencing, pallets and various engineered timber applications, right down to the sawdust which gets incorporated in the manufacture of OSB.

The scale and the efficiency of James Jones’ operation has been a key factor in helping the group emerge from the recession larger, stronger and more diverse than it was before - as the company’s Marketing Manager, Jon Stevenson explained to me recently.

He commented: “At our Timber Systems Division, which produces JJI-Joists, we have invested £4.5 million on a new finger-jointing line and upgrading the plant as a whole in order to increase production capacity; and to do it at even higher levels of efficiency and consistency. Significantly we have increased our market share and are now back at a level of business higher than the previous peak in 2007.”

One of the big areas of growth for James Jones has been in the increasing use of its JJI-Joists: achieved in part by delivering one hour CPD presentations to architectural practices across the country. The joists, with their OSB web and solid timber finger-jointed flanges are very structurally efficient and popular with contractors. Meanwhile social housing specifiers also like the ‘local availability’ which the company’s nationwide distributor network and regional technical support offers.

As part of the development of the range, the JJI-Joists are not only being offered as plot specific kits with spans in excess of ten metres possible for commercial scale buildings, but they are also being used to make up roof and floor cassettes. Metalwork supplier Simpsons Strong-Tie even makes use of them for easy to install floors for loft conversions,which it brands as I-Loft. The original JJI-Joist Intelli-Roof concept is frequently used for pre-fabricated roof structures, allowing the roof to be weathertight in hours.

Referring to the broad benefits of JJI-Joists over alternatives, Jon Stevenson explained: “With steel web joists the metalwork has to be produced to suit the specific application and cannot be altered, whereas if one of our distributors has a quantity of say, eight metre long I beams in stock and suddenly gets an order for four metre ones, they simply have to cut them in half. Also if you are looking at very low energy or PassivHaus developments, having a solid web cuts down airflow.

“Running services is no problem, though, as we offer guidance on where holes can be safely cut. And our finger-jointed flanges are easy to screw or nail into which you cannot do with LVL (laminated veneered lumber).

“In fact we not only have the largest standard range of any I-joist manufacturer, in terms of flange width and beam depth, meeting all required standards and available with either FSC or PEFC chain of custody, but ours is the only UK range that complies with PAS 2050: 2011. We also offer bespoke sizes, while the new finger-jointing line gives us even greater flexibility.”

Although most specifiers these days acknowledge timber to be a truly sustainable building material, it may interest social housing providers to learn that James Jones even has the software to calculate the carbon that is stored through the use of its JJI-Joists, with the average three bedroom family house giving a figure of around 390 kg CO2e. It really does appear that James Jones and its JJI-Joists tick all the boxes.

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