Summary
• Lyptus decking was an integral part of the Monaco Garden at this year’s Chelsea Flower Show.
• Lyptus is a hybrid of Eucalyptus grandis and Eucalyptus urophylla.
• Woodlink UK has supplied Lyptus for four years.
• TRADA Technology designed a test protocol to establish technical data.

Cyril Williams states unashamedly that he has “put heart and soul” into developing Lyptus hardwood decking, which burst so spectacularly onto the public stage at the Chelsea Flower Show in May.

The product featured in the Gold medal-winning Monaco Garden and, said BBC presenter Chris Beardshaw, “is set to revolutionise decking in our landscapes and gardens”.

It’s ironic perhaps that a few sound bites could endorse in minutes what it had taken the David & Goliath partnership of Woodlink UK and Weyerhaeuser months to do – give Lyptus credibility in the UK as a viable decking product.

Plantations

This hardwood, a hybrid of Eucalyptus grandis and Eucalyptus urophylla, is grown in managed plantations in South America and as such offers a sustainable alternative to traditional Tropical Timbers. It is PEFC-certified for good measure and, crucially, there is no seasonal variation in supply – it can be supplied all year round.

Initially, however, that cut little ice with the UK market. Mr Williams’s modest company in Essex had been a supplier of Weyerhaeuser’s FAS kiln-dried Lyptus lumber for nearly four years, but British buyers can be conservative and, despite a willingness to embrace sustainability, they are wary of the unknown. It was at this point that Woodlink UK looked hard at what the market needed.

“There seemed to be a gap for a fully-certified decking product with regular delivery,” said Mr Williams.

“We fervently believed that Lyptus was suitable for the job, but without independent technical data we had to accept that availability and green credentials were of little value if the product had no means to prove its performance.”

Dimensional stability is an important property for decking timbers, as excessive movement can result in warping which will cause a trip hazard and may lead to failure of fixings – as well as looking unsightly.

Woodlink UK was able to draw on research by its former parent company, Woodlink GmbH in Germany. The Hamburg Holz-Institut recommended that only boards of a certain density should be used, sapwood should be excluded and that the material should be dried to a moisture content of 10%. At its sophisticated mill near Vitoria in Brazil, Weyerhaeuser has worked with Woodlink in ensuring its production meets these stipulations.

Stumbling block

However, the Hamburg testing recommended that the optimum profile for decking should be 20x90mm to reduce risks of cupping or bowing resulting from moisture-related movement in situ. This, said Mr Williams, was another stumbling block.

“What 90% of the UK market wants is boards measuring 21x145mm, so we invested in further testing with TRADA Technology of the profiles the market demands here,” he said.

There are, however, no British Standards to provide limits on distortion of timber decking, or guidance on testing movement that occurs in deck boards when in service. TRADA Technology therefore designed a test protocol, using two test rigs to expose deck boards under ‘real life’ conditions and in a climate chamber designed to expose the decking boards to ‘harsh’ climate extremes.

Both rigs allowed for accurate monitoring of movement. These tests indicated that, when boards were fixed according to TRADA Technology’s guidance, set out in its Timber Decking Manual, “little distortion of the boards occurred”.

Stainless steel fixings

Interestingly, the testing also demonstrated that because of the high extractives content of this timber, Lyptus, like several other species such as cedar and oak, was susceptible to iron stain, but that this problem can be avoided if stainless steel fixings are used.

“Our long experience with providing guidance on the installation of timber decks, and evaluating performance of actual decks in service, enabled us to recognise the properties that required testing and devise methods to do this,” said TRADA Technology’s Dr Andy Pitman.

And the TRADA Technology test report is proving the key to opening new doors for Lyptus. Without it, Cyril Williams said, “Chelsea might not have happened. Now, potential buyers are clearly reassured that Lyptus can do the job as soon as they see the TRADA Technology name.”

• Hoppings Softwood Products is the UK distributor for Lyptus.