Summary
¦ Solid timber is the core material of the IWS system.
¦ Finger-jointed timber gives long span capacity.
¦ IWS has a wholly-owned supply chain.
¦ Four BM TRADA Q-Marks cover the system.
¦ A roofing system and a fire protection system will be launched soon.
When you get two people like Fraser Steele and Doug Cullen together talking about the future of timber systems the enthusiasm is infectious.
Mr Steele, who runs the importing and timber-processing business Glenalmond Timber, and former timber connector boss Mr Cullen have a shared vision of the future of timber systems called Intelligent Wood Systems (IWS), a new company which is positioning itself to bring something different to construction.
Launched at Ecobuild last year, IWS has already attracted praise from the likes of Professor Sean Smith of Napier University, who described the IWS System as “definitely the 2010 innovation”. It was also shortlisted for the TTJ Market Development Award last year.
In a nutshell, IWS is taking solid timber as its core material and pushing it to its limit by re-engineering to challenge the world of I-joists, open-web joists and other products in the floor, wall and roof systems market.
Mr Steele has been quoted before in TTJ lamenting the way I-joists have taken solid wood’s market share in the structural floors market. His desire to fight back led to the development of the successful super-dried, finger-jointed and water-repellent Ultrajoist, a distinctive blue-coloured timber joist which could match the spans of I-joists.
His quest for ever-higher performing timbers led to research into commercial yields for C30 and higher grades with Scandinavian sawmills (Stora Enso).
“But how could we engineer it into systems?” said Mr Steele. “I was at the limit and had gone as far as I could with the idea. The key was getting into engineered wood products. We had a value-added product that could be substituted for glulam and LVL, but would only be a component part in someone else’s system.”
Technical challenge
At this time, Doug Cullen asked him for a technical challenge. “Take a 9in solid floor joist, cut a 5in hole out of it and lose no performance,” was Mr Steele’s reply.
The answer was to use nailplates to strengthen the joist around the large service hole.
Both men realised their thinking was closely aligned and a partnership was born combining Mr Steele’s expertise in processing and distribution with Mr Cullen’s connector expertise and contacts in the housebuilding industry.
Since then IWS has undergone a seven-figure investment, including extensive R&D, testing, accreditation, the recruitment of 11 staff and setting up its 20,000ft² operation at Glenrothes, featuring two Hundegger CNC saws and an AV Birch press.
Software programs linked to the Hundeggers include C4Ci’s iPro (for floor systems) and ITW-Industry’s hsbCAD for integrated panelised designs.
IWS has recruited experienced consulting structural engineers Milner Associates to aid the development of the IWS holistic building system and will shortly launch a fire protection system to address the recent concern of timber frame site construction fires. It will also have a significant presence at Ecobuild in March.
Completed projects
Several IWS floor systems projects have also been completed, including a nine-block, five-storey student accommodation development in Exeter, erected by Frame UK, as well as other challenging projects.
“Some people innovate within their own existing product range but we are doing something entirely new,” said Mr Cullen. “The IWS strategy is much more than just delivering products; it’s creating an infrastructure to deliver those innovations.”
This infrastructure, he added, involved a wholly-owned supply chain – Glenalmond’s import of timber and processing/treatment to be manufactured into systems at IWS, as well as the convenience of testing at the nearby BPAC UKAS-accredited laboratory.
“It’s a closed loop, we are absolutely self-sufficient,” said Mr Cullen.
A major component part of the IWS System is IWS-Ultra timbers which are super-dried to a 12-14% moisture content and processed into 38 and 45mm widths and 220 and 245mm depths. IWS has developed its own grading system to differentiate itself – IWS-2, IWS-4 and IWS-5 – and BM TRADA has issued a Q-Mark covering the grades, strength and moisture content.
IWS says the system does not require backer, filler or squash blocks or ply gusset plates and reduces the range of connectors required. Small holes can be made on or off site but larger service voids for cables, pipes and HVAC systems are pre-machined and special nail plates are used.
Finger-jointed timber
The finger-jointing process at Glenalmond’s Methven site takes pre-graded timber and joins them, allowing the timbers to be made into any length up to 12m.
There is still something of a misunderstanding in the timber trade about finger-jointed timber. In the UK it has been used in joinery timbers for a long time, but many traders still shy away from it in construction wood, despite evidence of its strength and the fact that the Germans have been using it for years (marketed as KVH timber).
Finger-jointing is carried out on a Weinig Grecon Dimter machine with an 80m³ capacity on an eight-hour shift. It is capable of finger-jointing a maximum size of 280x80mm and a minimum of 70x38mm.
The finger-joint of a C30 section was tested for strength during TTJ’s visit. It was the wood that eventually failed, not the finger-joint, after reaching a load well beyond the level required. The highest recent test result was a C30 finger-jointed section failing at 71.97N/mm² (target level being 31.5N/mm²).
Another feature of the IWS system is its ability to be top-hung like open-web joists.
IWS’s Hundegger Speed Cut 3, a five-axis saw, cuts the profiles for the top-hung details so the joists can be slotted into rim beams and trimmers, saving time and connectors required.
BM TRADA Q-Marks cover the top-hung detail, service void and finger-jointing.
Preservative treatment
Treatment is also an important part of the system and was developed in partnership with Arch Timber Protection. The low-pressure preservative treatment incorporates a water repellant designed to significantly reduce the moisture ingression through the construction phase, helping maintain dimensional stability.
A pale-blue colour is added in the process, giving the timbers their distinctive appearance.
On the acoustic front, testing by SRL has shown a performance up to 4dB better than current Building Regulations in England and Wales without insulation – using just a plasterboard ceiling, joist and chipboard floor. For separating floor applications, nine different floor build-up configurations have been formulated and tested.
The tests show IWS separating floor systems can achieve three credits in the Code for Sustainable Homes, compared with one for a standard timber floor. A Robust Detail is pending.
“In any building fabric, all problems come at junctions,” added Mr Cullen. “Five years ago it was just structural performance being addressed, now it’s also fire, acoustic and thermal considerations.”
IWS is addressing this by developing and testing solutions to meet all these challenges and is using “FAST – Fire, acoustic, structural and thermal” – in its marketing.
Patents have been applied for on many of the details to protect the intellectual property (IP), although Mr Cullen said continuous innovation was the most robust defence of IP.
He said it remained early days at IWS and the first year had concentrated on testing and achieving various certifications.
“Do not judge us on our performance in 2009, 2010 and 2011 but on 2012. In 2011 we are putting the finishing touches to our roof and wall systems. 2012 will be the first time people can see the full holistic solution and complete matrix of products from IWS.”
Floor systems are being manufactured at the Glenrothes factory, but Mr Cullen emphasised that IWS’s role was primarily as an R&D ‘hub’ company supplying key timber frame partners with the component parts. “We do not want to supply everybody, but to have commercial and technical partners,” he added.
He said IWS’s focus on differentiation could help timber frame companies offer something different and add value in an industry which has historically been low margin.
“During the next 10 years there will be a raft of solutions that will adopt a holistic approach, predominantly using timber, steel and concrete as their core. The most successful will likely be hybrid, utilising the product most suitable for the particular element.”
But does all this innovation, high quality raw material and additional engineering come with a prohibitive cost?
“It doesn’t necessarily have to cost more,” said Mr Cullen, pointing out that use of IWS at the Exeter project achieved a 50% improvement in production efficiency at the fabrication stage.
The IWS floor system would normally cost more than an I-joist equivalent but less than open web beams. “This is an engineered wood product; we are taking the raw material and optimising it.”
I-joists and open webs are great but there are limitations on all products. It’s all about identifying the benefits and drawbacks.”
Mr Cullen said there were many innovations in the construction trade but not all had the infrastructure to make them a commercial reality.
Passivhaus, he said, was interesting but was still only being used in very small pilot projects and he questioned its suitability for the UK. “But all our innovation is geared towards the mainstream,” he added.
He laments the loss of UK manufacturing to Asia and wants to see a resurgence in British innovation.
Fire protection
IWS is excited by the impending launch of its fire protection system, which aims to help reduce fire risk during the construction phase of timber frame buildings.
A sneak video preview to TTJ showed health and safety officials and fire brigade representatives watching a test fire in a mock timber frame construction site where the fire protection system was used. The blaze self extinguished.
“To enable people to continue building in timber frame is our ultimate aim,” said Martin Milner, of Milner Associates.
More details will be released shortly, but IWS hinted that it would use a different colour on its joists for people to identify their fire-resistant properties and in doing so meet the Fire Protection Association’s recommendation for a marking scheme.
Mr Cullen emphasised that the fire protection system and other IWS features were all aimed at improving building performance and on-site efficiency, without radically altering the construction process.
“Timber has never been used like this before,” added Mr Steele.
“We think it can challenge the way people will look at building systems and can encourage other people to take a similar approach.”
