Summary
• Wood fibre is a breathable product, going against the emphasis in the UK for airtight construction.
• National Building Technologies is bullish about prospects for its Pavatex brand.
• Ecological Building Systems has been involved in natural insulation for 10 years.
• Zero carbon homes of the future will need to combat conduction, radiation and convection.
The market for wood fibre in the UK was once the domain of the eco-friendly, specified out of conscience and vogue by self-builders prepared to take the long-term holistic view of total cost to the budget and planet.
Its use remains relatively low and there is yet to be a manufacturing base in the UK. However, sales are growing rapidly and are expected to continue the upward trend in 2012 for refurbishment, retrofit and private and public sector projects.
Wood fibre board, with its good thermal and acoustic insulation properties and ability to ‘breathe’, is becoming a popular choice for underlay, roof sarking and for internal and external sheathing; and in combination as a complementary system.
“If you had asked me 18 months ago, I would have said it was a niche market, but I don’t think so any more,” said Paul Ibbotson of eco-merchant Acara Concepts, which sells German-made Hofatex rigid boards. Mr Ibbotson, who with his brother Carl, runs sales and distribution operations in Dublin and Huddersfield, spotted wood fibre as a diversification from its eco-friendly cardboard and sand acoustic board.
“I went to an exhibition in Germany and was impressed with wood fibre,” he said. “We could see it was a small market but a growing one. The market is changing quite quickly and 2012 is going to be better than 2011. Obviously the state of the construction industry is out of our hands, but we have one or two good projects in the pipeline.”
Tony Pensom is managing director of National Building Technologies (NBT), based in Oakley, Buckinghamshire, which supplies batt and rigid board products under the Pavatex brand, with a portfolio of commercial, public sector and residential projects to its credit. He is bullish about the product and the market.
“In years to come, wood fibre board will be parked out there up against the plasterboard,” he said. “Just when, I don’t think anybody can say yet.
“Our business has grown significantly this year,” he continued. “Obviously demand in construction overall will be weak and social housing thin, but we don’t see any reason why the growth for wood fibre should not continue and we are investing and boosting our sales force.”
Manufacturing process
Wood fibre is a common construction material in Scandinavia, central Europe, northern Italy and France. The core raw material is forest thinnings and sawmill by-products converted into rigid panels and flexible batts using the material’s own lignin as a binder.
Board is made using wet or dry manufacturing processes. In addition to water, heat and pressure, thicker wet-produced boards also require gluing with natural resins or modified starch. Various additives are also used for specific applications, such as latex for water resistance.
Manufacturers using the dry process of pressure with a synthetic binder believe this board requires 40% less energy to produce. Products range from 10mm up to 240mm and in densities typically from 150-260kg/m³, depending on application.
Acara chose Hofatex for the wet manufacturing process using 98% wood fibre and 2% natural binders. This combination, Mr Ibbotson said, provides the thermal mass properties needed to be able to store heat and moisture and release them without the board losing any thermal values.
Penny Randell, business development manager of Ecological Building Systems (EBS), supplier of dry-processed Gutex in the UK, said its process not only gives energy savings, but also provides a single ply board up to 240mm thickness.
“The wet process produces a laminate,” she said. “The single ply is easier to work with onsite in terms of cutting and is very efficient in terms of insulation.
“There is interest from architects, and builders are becoming attracted to board for sarking because there is a 22mm board to thermally upgrade the roof and make a more efficient structure. I don’t think, though, that there is any one application doing better than another. Upgrading single skin walls is an area that’s becoming more popular, especially with conservation bodies.”
Breathable product
Wood fibre is a breathable product, which goes against the emphasis in the UK on “airtight” construction. The merits for each can be argued in a series of calculations based on the relationship between accredited values and specifications. Last year NBT introduced WUFI moisture modelling software to allow it to demonstrate the integrity of wood fibre insulation. It takes into account the properties of each material within a designed envelope, as well as the building location, orientation and local climate.
EBS has been involved in natural insulation for 10 years. “We have put an awful lot of work in and, also, the market has reached a point where the building that is going on at the moment is low carbon and low impact,” said Ms Randell. “Diffusion open building – we don’t like to use ‘breathable’ – has a good customer base.”
Matthew King, managing director of ACTIS UK, agrees. “In the future, very high thermal requirements will require a more holistic approach, which will make combining different types of insulation materials necessary. Zero carbon homes will need to fight conduction, radiation and convection.”
“The [wood fibre] density is higher than in other fibre-thick insulation products,” he added. “It improves thermal and acoustic performance due to the combination of density and airtightness, and it gives better protection from compression in the long term. The inside air keeps clear as wood fibre allows the water vapour to leave the house and to regulate the hygrometry.”
“I think the market will just continue to grow,” said Mr Ibbotson. “The product development is in composite boards, more combinations of materials including wood fibre, all breathable.”
Price differential
Sonae, which produces the award-winning Agepan brand, manufactured in Germany by Glunz, still considers the products niche and part of a wider portfolio supported by specialist product teams. It sees the market reliant on design and specification and agrees it has been difficult to convince potential consumers to pay more.
“We believe these products are niche and will not sell through general merchants,” said a spokesperson. “We can supply the requirements of the market from European manufacturing sources. The market outlook for 2012 is limited growth due to competition from other products and comparative costs.”
Mr Ibbotson disagrees and believes it is a merchantable product, although he admits price remains as issue. Acara has stock on the ground with distributors and said maximum turnaround time was 10 days. Wickes, Travis Perkins and other larger merchants are supplying the board alongside eco-merchants. In the timber merchant sector, suppliers include Panel Agency, EH Smith Builders Merchants Ltd and Elliotts.
Production expanding
Since France took up the wood fibre baton, Steico and ACTIS have opened plants there and Homatherm is due to be in production this year.
Ms Randell believes UK manufacture is unlikely in the near future. “I doubt anyone will make the investment,” she said. “Gutex manufactures in the Black Forest in Germany where it’s very mainstream. We bring in a container every week, we try to keep a good stock and generally we can get it onsite in two to three days.”
ACTIS also has no plans to begin production in the UK, but Mr King believes wood fibre is a fast-growing market for both its eco-friendly advantages as well as its user-friendly advantages. “We have a complete range of products developed to answer the full variety of applications,” he said. “The general trend for the eco-friendly, eco-designed and user-friendly products such as our Sylvactis range keeps ACTIS confident in terms of sales during 2012.”
For NBT, looking to commercial, public sector and residential projects, price is wrapped up in a complex sell. Mr Pensom said selling wood fibre was a three-pronged battle of winning the specification from the architect, holding on to it with the contractor and ensuring the onsite work is handled correctly.
“Our position in the market is that we are offering a high-spec solution,” he said. “We are not in the market to sell a cheap way of building. If you go back in time, wood fibre was a green, eco-friendly ‘cuddly’ material. But we have moved on. It is a high performance and simple-to-use construction system. Certainly if you lay a square metre of our product against a square metre of a conventional product, ours will be more expensive. But if you look at it from the point of view of getting the building to do what you want it to do then the price comes down significantly.”
