Avoiding destruction in your construction

This 8km, 15 year old road in East Kalimantan is due to be shipped off to Bali and replaced with new illegal Ulin wood

In today’s ever-globalising world, it is hard for the discerning consumer to know where the wood they buy comes from. How do we get reliable information the wood’s origins, particularly when production is increasingly less localised and further away from the point of sale?

It is not easy, but it is possible.

The current laws for both new and reclaimed wood are, quite frankly, not that great and wide open to loopholes, as a recent trip to Kalimantan showed me. Exploiting a 2008 regulation from the Ministry of Forestry on inter-island trading of Ulin (Kalimantan Ironwood), I met with traders who were busy setting up deals with communities to replace their 15 year-old Ulin roads and bridges with new Ulin, only to sell the old stuff to the Bali reclaimed wood market! The old wood was pulled up as the new stuff was being simultaneously laid down. As one trader said, ‘We can’t send it out of Kalimantan, but we can replace the old wood with new and send that out instead!’

Much of this imported reclaimed wood ends up in the yards of reclaimed wood wholesalers in Denpasar, who supply raw material to many projects and retailers on Bali.

What concerns me is the possibility that the demand for reclaimed wood in Bali and elsewhere is actually fueling greater destruction of the forests, instead of the reverse. We got into the reclaimed wood trade because we saw it as a way to re-use an old and valuable material, thus reducing demand on the need for new wood. The average punter we meet generally buys recycled timber in an effort to help the planet.

The government was obviously concerned to when in mid 2007 in an effort to ward off the extinction of Ulin, it froze all harvesting and trade of the species and instigated an island-wide inventory of remaining stands in natural forest. The moratorium on the harvesting and trade of Ulin lasted until mid-2008, when it was replaced by a new law that limited export of Ulin only to a handful of Kalimantan-based timber companies who had existing stocks of Ulin in their forest concessions.

Current regulations require that Ulin traders obtain an endorsement from the BRIK (Forest Industry Revitalisation Agency) and a permit (PROKALINDO) to export Ulin out of Kalimantan. Only a handful of companies currently hold this permit. This has made it very difficult for new Ulin traders to find export markets for their wood.

Reclaimed wood exports require all sorts of permit processes of their own, including site inspection by the forestry department, police and forestry permits and so on. But generally speaking, it is relatively simple for the trained eye to differentiate new wood from recycled.

The big issue is of course sustainability. It was unsustainable and rampant exploitation that led the government to implement a law to restrict Ulin trading in the first place. Ulin has a 50 year in ground rating, which means we can expect a heartwood post to last 50 years, or more if it above ground. Growing at around half a centimetre a year, a 5 x 20 board would be cut from a tree that is at least 40 years old. Roughly speaking, a sustainable cutting cycle for Ulin would need to be at least 50 years. We are all for wood being used by local communities for appropriate applications. But what will this community do when in another 15 years when the roads need replacing again and there is no wood left?

So here are the three things you need to make sure your wood is legitimate reclaimed wood:

1. Ensure your supplier can provide evidence of the original structure the wood came from and its location (photographs or documentation)
2. Ensure that the original structure was not replaced with new wood when it was demolished
3. Only buy from trusted suppliers that can comprehensively and satisfactorily respond to your queries

Building termites out

I was recently called over to a client’s house to take a look at a pool deck that was installed a year previous using reclaimed wood that the supplier had advised was Ulin (Kalimantan ironwood).The deck was literally crumbling and on the surface showed evidence of rot and termite infestation. The installation had all the classic signs of bad building practices and what NOT to do in exterior wood applications!

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The enemy of wood... subterranean termites

When building with timbers outside there are 3 main things that we must protect against:
1) Solar degradation, 2) Rot and 3) Termites. I will talk more about sun and rain in forthcoming newsletters, but for the moment lets focus on termites.

There is a myth that some timbers are termite proof, this is simply not true. Certainly some timbers like Ulin (Eusideroxylon zwageri) are less attractive to termites as their heartwood contains specific extractives that have anti decay and insect resistant characteristics. Untreated Ulin heartwood posts are expected to last 50 years in ground contact, giving this timber the distinction of being one of the most durable timbers in the world. For sure this timber is particularly unattractive to termites, but it is not true to say that it is immune to an eventual attack from termites.

The best way to stop termite infestation is by understanding how termites like to live and build things that don’t suit their lifestyle. Although termites need water, they can’t actually drink, instead they absorb it either through the food they eat, or through a waxy layer on their outer skin. Hence if you design your building so all timber is separated by a visual barrier from any water source, you will at least be able to see them coming and going from water to food and stop them in their tracks. A good example of visual barriers are:

• Reinforced concrete slab with an exposed slab edge (that’s a slab with no cracks greater than 1.2mm (the width of a skinny termite). Termites will have to crawl over and around the slab, to go from water to food, hence you can just check your slab edge regularly.
• Steel stirrups or shoes on the bottom of posts, so the steel enters the ground and not the timber
• Flat metal sheet caps on top of the brick columns under your house. (known as Ant Caps). 
• All of these measures are environmentally friendly work forever at no running cost and all you have to do is a regular inspection.

Most of the termites that attack buildings are subterranean termites, living underground, then coming up inside trees and houses to eat dead wood, getting their water from moist ground contact. Subterranean termites cant crawl about in the open and will have to build mud tunnels to protect them from the sun, making their intrusion into your house much easier to detect and treat. In the tropics we also have arboreal and air born termites that can fly into your home. Again though as before the golden rule is that they all need to gain access to water.

A common practice in Indonesia is to install timber decks and stairs directly onto concrete slabs. This builder had closed the edges of the steps with a small wall of concrete, which had the dual impact of not letting light and air in, and trapping water under the timber boards. This is a big no-no if you want to increase the life of your timber and avoid termites. Exterior timber really needs to be kept dry and be installed in a way that allows good airflow and access. This is particularly important in the tropics, where there is a relatively higher decay and inherent termite hazard than in the temperate zones. In this case, the termites had simply tunneled up from the slab and into the boards.

Remember it’s the combination of water and timber that cause most trouble, so design your house so the timber stays nice and dry and preferably out of the sun. And build your house so it’s comfortable for you to live in but not for termites. Darrin, who runs Termite Web, one of the best information hubs on termites around (http://www.termiteweb.com) advises that we can learn a lot from traditional house building practices in the villages in Southeast Asia, as these communities these have co-existed with termites for hundreds and thousands of years. He reckons stilt building prevents 90% of common termite problems (subterranean termites), because it controls the entry points for termites very well.

Throughout the world there are many agents selling complicated systems for termite protection, including a great range of toxic chemicals and the like. These systems vary from outright stupid to out right dangerous, with a fair amount of crossover in between. Fancy visual barriers i.e. things that termites cant crawl through but must crawl round do work, but are often expensive and often a complex solution to a simple problem. When in doubt fall back on the good old fashioned three step rule:

1. Separate timber from water (including ground) with a visual barrier
2. Regularly check the visual barrier
3. If there is an infestation, bait the termites with a nice soft piece of timber soaked in an accumulative poison that they can take back home and feed the queen to kill off the hive. Killing off 1 or even 1 million termites won’t stop them, killing off their one queen will.

Another small eco-tip… world timber supplies would be much healthier if we simply used the right timber for the right application. So build that one-off handmade guitar out of some amazing beautiful rainforest timber, but don’t waste that timber making wood pulp for paper or packing crates! And use a good quality, preferable second hand exterior grade timber in an exterior application and try not to waste it on interior uses where a less resistant more common and perhaps even prettier timber will do.

By the way, we checked the termite infested timber that my client had installed and it turned out it was NOT ulin… it was a less-resistant Shorea species completely unsuitable for external applications!

For more information read “Building out Termites” by Robert Verkerk

Thanks to Dave Hodgkin and Darrin from Termite Web for help with this article.

Wooden floors have a timeless quality

Wooden floors have a timeless quality that can change the whole look and feel of a building. We all love wooden floors, but what do we need to be aware of when shopping for flooring to get the best results?

Living in the wet tropics, one of the main considerations we need to be mindful of is the effects of moisture on wood in our construction. Wood floors are no exception. All wood has a moisture rating which changes as the temperature and moisture in the air increases and decreases with the seasons. Wood is a natural product so it expands and contracts in response to these changes.

The general and very simple rule of thumb with wood flooring is never put solid wood flooring in wet or moisture-susceptible areas: water and wood do not mix. This includes in areas that are below grade such as basements or cellars. Water degrades wood, and constant or prolonged expose can cause cracks, cupping and buckling.

The method you use for floor installation will depend on how and where you are installing your floor. The three common installation sites are described as below grade, on grade or above grade. For floors at the on-grade or ground level, it is common to nail or screw the boards onto small battens which have been nailed or screwed into a concrete subfloor. This is all fine, but remembers to seal your concrete slab with plastic sheeting first to prevent the enemy of the wood floor, rising damp. Just like we can take steps to build out termites, we can also take steps to eliminate moisture intrusion. Sealing your concrete slab should be a standard building practice in the wet tropics, but unfortunately this is not the case hence you will need to request this specifically.

For floors at the above grade level, commonly the flooring will rest on floor joists which are sitting on bigger beams known as bearers. A floor that rests on joists as opposed to on battens or one that is glued directly onto the floor is known as a ‘floating floor’. It is a good idea to check what kind or structural support you need when shopping for flooring as this cost needs to be calculated to get the final per square meter price.

Some tips on selecting and installing wood floors:

• Ensure your boards finished to an even thickness at a minimum. This will make it a lot easier to install.
• For below and on grade flooring, check the moisture content of the wood prior to installing if possible and make sure there is no possibility of moisture intrusion
• Solid wood flooring shrinks in dry environments and expands in wetter environments and most of the expansion happens along the growth rings (tangentially), and about half as much across the rings (radially). Get flooring which has small grooves on the underside, known as “back relief” to allow for this swelling and shrinkage
• Remember that wide boards tend to expand and contract more than narrow boards

Have fun!

Quoting Alex Ryan, Kaltimber Founder

“One of the reasons we deplete our resources so quickly is because we don’t design in a clever way. If we can put longevity into the design phase, I believe there will always be a market for reusing, reclaiming and designing around the material’s original state. I know that is not always possible, but it is what I am trying to promote.”

— Alex Ryan, Kaltimber Founder

Building to last protects forests

We made it into The Jakarta Post!