Where the heart is

Summary
• Materials offering high efficiency and low waste are coming to the fore.
• Demand for laminated sections has progressed rapidly over the last five years.
• SCA opened a dedicated window component factory two years ago.
• Material innovation is starting to focus on selected heartwood sections.

In recent years, timber production efficiencies have created a phase-shift in the material used for timber windows and doors. This wave of innovation is still travelling, driving enhanced business performance and reducing waste.

Recognition and acceptance of laminated sections in the UK has been influenced by the British Woodworking Federation’s work with Defra to reduce timber waste from the joinery industry. “Waste costs are considerable for small businesses. With campaigns such as WRAP’s Halving Waste to Landfill putting additional pressure on the construction sector, it’s not surprising that materials offering high efficiency are coming to the fore,” said Simon Thurman, SCA Timber Supply’s industrial components manager.

Forward-thinking firms have been using laminated materials for some years and are now encouraging others to do the same to improve the public’s perception of joinery products.

Engineered timber

“We’ve been using laminated materials for 10 years as they combine greater stability with reduced waste,” said Chris Wood, sales and marketing director at Mumford & Wood. “We use laminated larch or laminated oak with a hardwood cill as this means we don’t need chemical treatments and can create a product with a definable quality finish.

“We also use laminated materials in doors as their lack of movement reduces warranty issues,” he added. “For the future we’ve been trialling modified timbers as they are less dense and may offer better window energy ratings than redwood, though we’re still in the testing phase. We’re also looking at a number of other material options.

“As members of the Wood Window Alliance we’ve been encouraging smaller joinery manufacturers to increase their use of laminated sections,” continued Mr Wood. “Use of knotty material lets the industry down; we need to bring everyone onto the same playing field to maintain the reputation of timber windows. We’ve been working with national suppliers to achieve standardised products, which can be offered to smaller joinery firms, especially in sash window sections, which form a niche market here in the UK.”

Demand for laminated sections has progressed rapidly in the past five years and SCA has seen its sales of these products increase dramatically. This in part influenced its decision to open a dedicated window component factory in Sweden two years ago. Industrial wood components of all kinds now form a large proportion of SCA Timber’s sales.

“Perceptions of laminates have changed radically amongst window manufacturers, thanks to the Wood Window Alliance,” said Mr Thurman. “There’s greater understanding, for example, that finger-jointed laminated sections are technically sophisticated. Small to medium-sized manufacturers are now beginning to see cost benefits from using these products, and are gradually introducing them to their production.”

Glyn Ducker, managing director of GD Woodworking, is one such manufacturer. “We have changed over all our doorset production to laminated timber and have found that there is virtually no waste,” he said. “Laminated products give a better quality end product as there are no knots to contend with and each component is perfectly straight.”

Even though prices for engineered wood window components are substantially higher, joinery companies make significant operational savings which offset the level of investment. Time spent in repairing sections during manufacture is negligible, increasing available time for production. Standing grain – tailored to suit the direction of machining – also contributes to producing a better paint finish.

Material innovation

Apart from treatment modification, where can material innovation go next for softwood window manufacturers? Simon Thurman sees increasing interest in selected heartwood: “European manufacturers are already substantially ahead here,” he said. “Selected heartwood is a different approach to quality. Where the UK market is driven by the aesthetic appearance of wood, Continental manufacturers look first at the durability of the material.”

SCA has invested in X-ray technology at its Munksund and Bollsta sawmills to capture its share of the market for selected heartwood sections. The machinery measures the heartwood location within the logs, its relative density, and the amount of heartwood present, setting aside logs with sufficiently valuable content. “This is to enable the saws to be aligned perfectly to yield as much value as possible,” said Mr Thurman. At SCA Munksund, high heartwood content material goes straight into the window component manufacturing line.

This technological innovation came about through co-operation between SCA and university partners in Sweden, but Mr Thurman also believes future advances will equally come through the creative minds active at SCA’s sawmills. “Our production is driven by optimisation of our valuable forest resources. Improving yield, and the value of that yield, will no doubt create new options for joinery producers. And as the UK is one of SCA Timber’s main markets, joinery producers here will be amongst the first to benefit from future advances,” he said.