The photograph above may not be what you would expect. The outdoor bench in this detail is not made from an unsustainably harvested tropical hardwood. The wood itself is actually maple, a widely available species that can be farmed and harvested without ripping up acres of rainforest. But maple and many other similar woods are too susceptible to decay and rot when used unprotected outdoors. The usual alternative has been treatment with chemical pressure treatment. Now, through a method called kebonization, a Norwegian company, Kebony ASA, treats soft woods in a non-toxic process that allows readily available woods to be used for outdoor uses.
The process of kebonization is similar to pressure treating wood (which is another way to make soft woods usable for exterior use). But, instead of soaking the wood in toxic chemicals like chromated copper arsenate (CCA, which is now banned for most uses in the US and the EU) or alkaline copper quaternary compounds (ACQ, the most widely used replacement for CCA after the ban), it is instead soaked in furfuryl alcohol, a waste byproduct from sugar cane. There are no special handling requirements or precautions needed to deal with waste from this wood, and it can be disposed of just like any other untreated wood.
During the kebonization process, the alcohol becomes a resin that reinforces the cells of the wood. The result is a wood with excellent outdoor exposure tolerance like teak or mahogany, but with a harder surface than many of the tropical woods that it replaces. The wood also naturally fades to a silvery-grey color much like those tropical woods, as well. Maple is used in place of teak, and southern yellow pine is used in place of ipe.
Kebony wood can also be used for building siding. In fact, it is so water and weather resistant that it is even been used for building roofs and for boat decking (see below). The process also makes the wood less prone to swelling due to moisture. There is no necessity to paint Kebony wood, and it can withstand decades of exposure to the weather before any maintenance is necessary. According to the company, a kebony wood roof can last for 30 years before any maintenance is required.
Kebony wood is probably not going to do much for you in terms of obtaining LEED credits. The material is imported from Europe. There is no indication on the company's website of the material being FSC certified wood, either. Still, it is a natural wood product. More importantly, it is a wood product that is durable without having toxic additives. And it is obtained without clearcutting tropical rainforests.
Even more pictures are available on the Kebony website.
Photo credits: Kebony ASA.
Very nice. There are also heavily pressed recycled paper products that can be used for park benches as well as indoor countertops. That way you are just recycling a tree that was already cut down instead of falling a new one.
-Tyler
Hopefully if demand in the US becomes high enough they will start using this process here too some day. Great info.
Isn’t furfuryl alcohol rocket fuel? How can this be safe? Has a fire spread test been conducted? Do gases get released under intense heat?
I’m afraid that just because it’s NOT a tropical hardwood…people get crazy and think that it’s a safer product for a home…
To paraphrase the old Saturday Night Live joke, “Furfuryl alcohol: it’s a food additive AND a rocket fuel.” It’s food-grade material, but it self-ignites when combined with red or white fuming nitric acid. Self-igniting fuels simplify rocket design, which is why the combination is used.
Tyler, I don’t think pressed recycled paper would be suitable for decks, where the Kebony wood is. It’s useful for a very wide range of uses.
I’ve ordered samples of this from the US distributor, and I’ll post an update after I’ve had a chance to see the stuff in person.
Whom might their U.S. distributor be?
Kebony has a representative in the US. They are based in Virginia.
I’m not sure why they aren’t listed on the Kebony website. I e-mailed [email protected] to get in touch with them, and heard from them fairly promptly. Hoping to get the samples from them later this week.
I received the Kebony sample, a piece of 5/4 x 6 radius edge deckboard. I haven’t tried taking a tool to it yet. I do want to cut it and see if it is colored or stained all the way through, or if this piece was cut and then treated.
It certainly seems to have a harder surface than ordinary pine; you can push a thumbnail into pine, but not with this stuff.
The color seems not as rich as a hardwood, but not offensively so. I’d also like to see how it weathers, and how the color changes over time. My next step is going to be to cut it into two pieces, and set one part of it out to go through the winter outdoors and exposed to rain, sun, and snow.
The sustainability offered by American Hardwoods could help with the environmental issues which are facing the world – and this could be potentially useful in efforts to fight global warming.
Very nice, but this presents a problem for people who rely on making their living from harvesting and finishing tropical hardwood. This product may cause their families to go hungry.
Only the big logging companies gets profit from destroying the forest
[…] Plastic Lumber was favored as the best material for the substructure and either plastic lumber or Kebony treated wood for the surface. Southern yellow pine and sugar maple, both domestically grown in managed areas […]
Has anyone carried out a test on how quickly Kebony catches fire or a fire spread test.?
damn, never knew you could do that, and im a home improvement contractor
david sean,
http://www.youtube.com/watch?v=n6p8YSZskeE
[…] The photograph above may not be what you would expect. The outdoor bench in this detail is not made from an unsustainably harvested tropical hardwood. The wood itself is actually maple, a widely available species that can be farmed and harvested… […]