Innovation: Inventor and British backers poles apart: Building system that uses waste timber goes to the US

THE INVENTOR of a jointing and design system aimed at turning worthless timber into a construction material to rival steel and concrete has taken his idea to the United States after failing to raise commercial interest in Britain.

Dr Ibrahim al-Khattat has received European Union grants to finance the development of his system, which uses unprocessed poles to build large structures, with no restrictions on span or shape.

It also won the top invention award for a UK small business in a national competition organised by the Design Council and sponsored by Toshiba, the Japanese electronics company. Despite all this, the technique may have to be developed in the Midwest, because no one in Europe has been prepared to invest.

Dr al-Khattat says his construction system would allow Britain to cut its timber import bill, which stood at pounds 1.04bn in 1991, and capitalise on a vast volume of hardwood timber that would otherwise be discarded. The system uses poles of 13cm diameter or less that are removed as forest thinnings, and generally used as firewood, or left to rot. Even paper mills are not interested, because of the bark. As a result it would provide a much cheaper construction material than concrete, steel or sawn timber.

Dr al-Khattat says that the superior properties of such poles, in comparison with sawn timber, are well known to engineers, because the intact growth-ring structure of small- diameter poles makes them stronger weight-for-weight than sawn timber, which is weakened by slicing through the growth rings. But until Dr al-Khattat devised his system, in which poles are slotted at both ends into hollow metal connectors, there was no reliable method of jointing this type of timber - it tends to crack if bolted through the end, for example.

The structure is kept stable by steel wires that run through the metal connectors. The skeleton can be clad in any material. The poles do not have to be straight for the construction system to work.

Dr al-Khattat has also written stress-analysis and design software, taking advantage of the fact that the uniform internal structure of the poles means it is possible to predict their strength in the same way as that of a manufactured steel pole. He says this is the first time that a method for accurately predicting the performance of timber structures has been developed.

The first building to be constructed using the system was a 6m x 3m garage with three timber spans, at Dr al-Khattat's home in Clwyd, Wales. He refined the technique with the construction of a footbridge, also in his garden. His brother- in-law, David Jones, a director of Engineering Mechanics Innovation and Research (Emir), the company set up in 1988 to develop the system, says the bridge was built by hand, without cranes or other plant machinery, using two pieces of scaffolding borrowed from a neighbour. 'It's like building with a Lego set,' Mr Jones said. 'The pieces are slotted in one at a time and there is no heavy lifting.'

Emir also constructed a geodesic dome, which is used by Dyfed County Council as a woodland centre at the Scolton Heritage Park near Haverfordwest in Wales.

In these three structures the metal partitions are made of fabricated steel, although the components could be cast. Mr Jones says ease of construction and availability of material makes the technique suitable for agricultural buildings, as they can easily be extended, taken down and rebuilt as required. The system could form the basis of rural industries.

There are also environmental advantages. Finding a market for thinnings would improve woodland management and cut the demand for mature timber as a building material. Ease of construction would also make this a good way to build emergency shelters.

One other important attribute of these structures is that they are flexible, unlike concrete, for example. This makes them resistant to earthquakes, high winds and settling of the foundations.

But Emir has failed to find commercial backers, and at the beginning of this year Dr al- Khattat went to seek sponsorship in the US.

His son Zayd, also a director of Emir, says he has attracted the interest of entrepreneurs in Idaho who want to promote the system for weather-resistant structures. 'This is not only a new idea, it is radically different from existing structural methods. We have approached several construction companies, but the industry is conservative, in some ways rightly so. My father decided that the UK was not the place to bring out this system.'

Mr Jones said Emir was still interested in finding financial backers in Britain, but would market any products developed in the US.

(Photograph omitted)