Your decking is a great drug!

Ulin ironwood tree

Dayak ethnic group is the indigenous people of Kalimantan Island and mainly live in a remote area. Dayak ethnic group in West Kalimantan is divided into 151 subethnic groups and their languages are classified into 168 groups. Since their residential areas are isolated from other villages, they depend on their environment, especially, the forest. It functions as a place to meet their basic needs because they have the knowledge how to utilize natural resources. Especially, plants have been used as medicine to treat diseases. Therefore, medicinal plants are known as their local wisdom and survival knowledge related to environment. Nowadays, the utilization of medicinal plants is facing several threats due to the scarcity of this knowledge and forest condition. Generally, this knowledge of the utilization of medicinal plants is not well documented since it is orally transferred from generation to generation. While younger generation accepts new culture from outside of their village, the knowledge of medicinal plants is fading. Forest conversion also contributed to the decreasing number of medicinal plant species. Approximately 21.51% of 9,125,486 ha of forest that functions as the main habitat of medicinal plants in West Kalimantan have been lost since 2010. Therefore, to conserve the knowledge of medicinal plants, it is necessary for the Dayak people to use them continuously to treat diseases. The documentation of medicinal plants utilization of several Dayak sub-ethnic groups is already reported. Dayak Uud Danum means a Dayak sub-ethnic group who lives in the upstream areas of Ambalau and Serawai river of Sintang Regency. In Dayak Uud Danum community, people use 95 species of medicinal plants. One of them, Tebelion (Eusideroxylon zwageri) has been used to treat diseases such as diarrhea, fever and allergy as the decoction of leaves by hot water. These diseases often caused by infections induce inflammation. Therefore, these medicinal plant is suggested to have anti-inflammatory activity. Inflammation is one of causes of diarrhea and plays an important role in the allergic disease such as delayed-type hypersensitivity (DTH). Diarrhea is difficult to be fully recovered in a patient with an inflammatory bowel disease. Prolonged inflammation of intestine may lead to the increasing risk of colon cancer. Not only in cutaneous skin infection, but also in patients bearing transplanted tissues and tumors, DTH must be considered. Since both IFN-γ and TNF-α are involved in the inflammation of DTH and colon epithelial cells, it is useful to examine the anti-inflammatory effects of medicinal plants on DTH and the inflammation of colon epithelial cells. E. zwageri has anti-melanogenesis activity (Arung et al. 2009). The activity of their plant extracts was reported.

Medicinal plants have been used to treat diseases caused by the malfunction of the immune system. Many reports have been published to prove that chemical compounds from medicinal plants have immunosuppressive effects. Currently, it is well known that secondary metabolites from natural products such as medicinal plants have a broad spectrum of biological activities, and the anti-inflammatory activity is one of them. Flavonoid group, one group of secondary metabolites, has anti-inflammatory activity and is used to develop a new type anti-inflammatory agent. Recently, E. zwageri is identified to have bioactive compounds through phytochemical screening. It is reported to have alkaloid, phenolic, flavonoid, saponin and steroid compounds. Among these medicinal plants used in this study, there are various bioactive compounds that might contribute to the suppression of ear thickness in this model of DTH response. It is also conceivable that secondary metabolites of medicinal plants may have anti-inflammatory activities and affect to several pathways of various phases of inflammation. Presence of potent bioactive compounds such as phenolic and flavonoid compounds may contribute to antiinflammatory activities.

Inflammation has an important role as one of natural protection mechanism and it has a dual nature like a double edged sword. Over production of several inflammatory mediators leads to a chronic disease. Therefore, in order to explore anti-inflammatory reagents from natural products, various criteria must be applied to screen medicine. It is well known that many indigenous people around the world use medicinal plants as anti-inflammatory medicine to treat several diseases. In West Kalimantan Indonesia, although government has been providing adequate health facilities and modern medicines, some people who live in poverty or in remote areas from government health facilities still rely on traditional medicinal plants to treat diseases such as fever, allergy, and diarrhea. Dayak Uud Danum, indigenous people of West Kalimantan, Indonesia is one of the communities who still use and preserve knowledge of medicinal plants as their local wisdom. Through an ethnopharmacological approach, activities of many bioactive compounds from plants will be determined. Although E. zwageri has anti-inflammatory activities in term of suppressing delayed-type hypersensitivity, further experiments are necessary to determine the mechanisms of potential plant extracts to regulate the inflammation.


Additional info;

Although the seeds are poisonous, the fruit and seeds have medicinal uses, and are used locally to treat swellings. Seed extract was shown to have anti-melanogenetic properties, indicating a potential for use in skin-whitening cosmetics. The screening methods used were melanin formation inhibition assay using B16 melanoma cells. The extracts of Eusideroxylon zwageri (seed), showed DPPH radical-scavenging activity of more than 70 percent at 100 microg/ml and extracts of E. zwageri (seed, 100 microg/ml) strongly inhibited the melanin production of B16 melanoma cells without significant cytotoxicity. These findings indicate that this plant from Central Kalimantan are potential ingredients for skin-whitening cosmetics if their safety can be confirmed.



Source: Kuroshio Science, CABI Encyclopedia of Forest Trees, Journal of Natural Medicines v. 63(4): p. 473-480, 2009.

Butterfly joint, what is it?

A Butterfly joint is a type of joint used either to hold two or more wooden boards together or to keep two halves of a board that have already started to split from splitting further. They may also be used to stabilize the core of a knothole, preventing it from dropping out over time. They are also commonly used as decorative inlays for non structural aesthetic purposes.

A negative of the hole is cut out of the board the butterfly will be placed in and the butterfly is then fitted, keeping the joint together. The wood used for the butterfly is usually a contrasting wood but not always.

Butterfly joint have been used both in decorative and structural joints since ancient times. They were prominently used in construction of the Cairo Dahshur Boats, a type of Khufu shop from the Egyptian middle kingdom. They were also historically used in repairing cracks in dutch tabletops in the 18th century. This is where the other name of this type of joint, Dutchman joint, originates. The butterfly joint was installed across the crack to stabilize and inhibit further movement of the crack.

Another name is Dovetail key as it looks like two Dovetails opposed by their tips.


butterfly joint

The village where a curse protects the forest

Local tradition in Mungku Baru has kept high-value ironwood trees from being felled over the years.

Today, however, some of the trees lie in a timber company’s concession.

The villagers’ beliefs have been codified into customary law.

Although it is administratively part of Palangkaraya in Central Kalimantan, the village of Mungku Baru is far from the city in both distance and development. Cell phone signal is scarce, and there is no government electricity. Several houses have small solar panels, while others rely on generators for power – but 40,000 rupiah worth of fuel only lasts until 9 p.m.

Two hundred families live in Mungku Baru. Most are farmers, many have rubber plantations, some scour the forest for honey and traditional medicines.

“We also grow dry-land rice,” Anton, one of the villagers, told Mongabay. “We plant in October and harvest in March. It’s all organic. We don’t use chemical fertilizers.”

The most prized aspect of the village, however, is its rare ironwood forest. Known locally as ulin, Eusideroxylon zwageri is a high-value timber species and is often the first targeted by loggers. Its slow growth rate produces a tight grain that resists rot and termites. Ironwood buildings last for hundreds of years in the harsh wood-devouring climate of Indonesia.

The ironwood forest is located upriver of the village, besieged by PT Taiyoung Engreen, a timber company that is clear-cutting the surrounding forest. The company has, so far, respected the villagers’ rights to the land, leaving it untouched.

“The company has never disturbed our ironwood forest,” said Redie, one of the forest’s caretakers. “Therefore it is still in good condition.”

There are no roads or trails through the preserve, and unlike most rainforests still remaining in Kalimantan, there are still large-diameter trees and a wide diversity of other flora and fauna.

From this patch of land, the locals harvest several varieties of traditional medicine, such as iro, a fern used for treating liver ailments; tusuk kesong, a long tree root used for asthma; kelanis, a general purpose medicine; gensing, used for arthritis; belawan bark, good for diarrhea; semar, also used for asthma; and ants nests, for treating mumps. In addition, the locals believe the roots of the ironwood tree can be consumed to increase endurance.

“We don’t sell these medicines, but use them for our own needs,” Redie explained. “In the future, we might start a small business [in medicinals].”

A recent survey of the 500-hectare ironwood forest found 192 ulin trees greater than 20 centimeters in diameter. Despite a ban on export of new Kalimantan ironwood, vendors on the Chinese e-commerce site Alibaba still list Kalimantan ulin at upwards of $3,000 per cubic meter. At this price, rough calculations place the value of those trees at well over $360,000. Luckily with the recent redline on import/export it had became increasingly difficult to export new Ulin. Only reclaim Ulin from disused structure is officially authorized for export.

Even so, the locals are not interested in selling. They consider the forest sacred and rarely enter the preserve.

According to Hester Talajan, the traditional historian of the village, their ancestors saw that people were rapidly cutting the forest and worried there would soon be nothing left. To protect the forest, the ancestors called upon the spirits to guard it, stating that whoever dared to cut the trees would meet with untold disasters that would affect their family for generations.

This curse was then codified into customary law, a system of governance and penalties determined at the village level according to traditional rules. In the past, the fines for breaking the law were paid for with goods and crops, but now they consist of monetary penalties. One kati, or unit of punishment, costs 100,000 rupiah. If someone is found guilty of cutting a tree in the protected forest, the village elders and the forest guardians will determine how many kati the offense warrants.

The people of Mungku Baru formally established an ironwood forest governing body in September 2014. However, this group, and the village’s claim to the land, has yet to be officially recognized by the Indonesian government. This crucial step would provide long-term security and much needed funding to patrol the forest and protect it from outside threats.

“Our expectations are high,” said Aries Antoni, the village head. “We hope to protect and cultivate the forest. We wish to work together with other groups, but as of now we still have no legal claim to the land.”

This puts the village in a difficult position as competing interests continually threaten the ironwood forest’s fate. For example, although the timber company has respected the village’s wishes up until now, Aries fears they will change their mind once they finish harvesting the rest of their concession.

Further, another group has claimed that the ironwood forest rightfully belongs to them.

“It’s not true,” Aries said. “They staked their claim without any public discussion, and don’t care about the interests of Mungku Baru.”

However, without official government recognition of Mungku Baru’s claim, the fate of the forest remains uncertain.


Photo by Indra Nugraha.

Photo by Indra Nugraha.




Original article at

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!


Wooden floor & stairs

Wooden floor & stairs

I felt this great article from April 2015 was getting slowly but surely lost in time, hope you enjoyed re-reading it!

Show me your Ulin and I'll tell you who you are

Take two minutes to read this and share it with friends.

With today internet access everybody suddenly became an expert in every single possible subject and work.

It is unfortunately the same for reclaim wood.

As it comes out, we mostly only know what we think we know but don’t know much in the end. This over confidence leads us to buy good material and do good deals of fake stuff that we ultimately regret.

How many times have we been contacted by desperate hotels, restaurants or individuals because they had problems with their “reclaim Ulin from Kalimantandecking and/or flooring. Once on site you realize the reasons of that despair. Varnish falling off (only a full sanding and recoating can help, no cheap solution), fully cracked wood (impossible to fix) not to mention long splits (sometimes up to 40% of the board!!!) and rusty nails (discoloring the wood in the process).

The worst being it isn’t even Ulin from Kalimantan and most often not even reclaim.

A commonly sold Ulin Kalimantan so called reclaim is what we call “rendaman”. It is a process in which they cut boards size planks into new Ulin trunk, put some nails on it, oil it and put it into mud for a couple of month. Voila! The real Ulin Kalimantan board will look, from the outside, like a genuine reclaim board. But it is not at all.

Wood continues to move as it is in contact with its surrounding environment (humidity, temperature). Reclaim wood tend to be an already dry wood and will move less. A new wood is still full of all its elements and not yet at EMC meaning disastrous consequences for construction site (cupping, bending, bowing, crack, split). It will look beautiful the first few months…unfortunately only the first few months then you are in for a financial treat to fix your nightmare decking or flooring.

A recent test on our facebook page was asking to recognize an Ulin plank in between two boards. One was Bengkirai, the other was Ulin. 70% of the voters choose the Bengkirai plank as being Ulin…

Bengkirai can look like Ulin but its quality as an outdoor product are far behind those of Ulin Kalimantan.

I write Ulin Kalimantan because you can also find Ulin Sulawesi. This last Ulin is of a much lower quality than the one from Kalimantan and will tend to crack quickly if not to split. Would you like to know more about this Ulin Sulawesi you can read this interesting article.

Luckily some honest sellers are offering a good quality wood in its raw form or processed but I’d advise you to make sure 100% that you know what you are buying. Dirty and muddy doesn’t mean reclaim.

On a more personal note, out of curiosity I went somewhere in Bali where you can find many reclaim Ulin sellers. I found half of it to be rendaman, other sellers were offering real poor quality but genuinely reclaim Ulin (can’t tell if it was from Sulawesi or Kalimantan) and only one person was selling genuine reclaim Ulin of good quality. Took us a full day to go around all places and found only one place where we could have bought good wood.

On a more commercial note, we at Kaltimber, offer real reclaim Ulin from Kalimantan. We work with the Forest ministry to get all our legal documentations, we know where the wood comes from and what structure it was dismantled from. We don’t do rendaman or Ulin Sulawesi, our focus is genuine reclaim Ulin from Kalimantan Timur. We offer years of experience and are always happy to advise and help for free.

Buying wood should be a non stressful investment and enjoying it should last for decades.

Our Ulin being checked before being given green light to leave Kalimantan

Our Ulin being checked before being given green light to leave Kalimantan

Ulin vs Ulin

So many customers get tricked and buy real reclaimed Ulin which is nether real nor reclaimed and not even Ulin.
We offer a wide range of services at Kaltimber and we can guarantee as well as prove the origin and type of wood we sale.
Don't fall for super cheap price offer while buying a rare material.
Next Monday we will publish an article regarding Ulin and the risks of buying fake reclaim.


What is the EMC and why is it important

The equilibrium moisture content (EMC) of a material surrounded at least partially by air is the moisture content at which the material is neither gaining nor losing moisture. The value of the EMC depends on the material and the relative humidity and temperature of the air with which it is in contact. The speed with which it is approached depends on the properties of the material, the surface-area-to-volume ratio of its shape, and the speed with which humidity is carried away or towards the material (e.g. diffusion in stagnant air or convection in moving air).

For anyone who works with wood products on a regular basis, there are a couple of reasons why it is important to know the point at which wood will reach its EMC, as well as the average moisture content of the region where the wood will be used.

As wood absorbs or bleeds moisture, it will expand or contract. The more moisture that is absorbed or displaced, the more severe the expansion/contraction of the wood product. This can cause, as seen in previous topics, cupping, bowing and another deformation of wood as well as cracks and even splits.

It can take a few days for wood to fully acclimate to a given environment, depending on the original moisture content of the wood, the temperature of the new environment, and the relative humidity of the area. Generally speaking, the greater the difference between the moisture content of the wood and the EMC point of the wood, the longer it will take to fully acclimate.

Moisture meter as used in Kaltimber

Moisture meter as used in Kaltimber

Make sure to check with your wood supplier what is their wood EMC and what the humidity of its future environment is.

Reclaim wood such as Ulin tend to be already really dry but its high density makes it harder to acclimate to a new environment. We are not talking about a few days in this specific case but more a couple of weeks to avoid any long term issue.

Hardwood and Softwood, what is the difference?

red elm end grain

Hardwood is not necessarily a harder material (more dense) and a softwood is not necessarily a softer material (less dense).

Different types of construction projects call for different kinds of timber, both hardwood and softwood are used for everything from structural to decorative.

Softwood and hardwood are distinguished botanically in terms of their reproduction, not by their end use or appearance. All trees reproduce by producing seeds, but the seed structure varies.

Softwood trees are known as a gymnosperm. They reproduce by forming cones which emit pollen to be spread by the wind to other trees. Pollinated trees form naked seeds which are dropped to the ground or borne on the wind so that new trees can grow elsewhere.

A hardwood is an angiosperm. Angiosperms usually form flowers to reproduce. Birds and insects attracted to the flowers carry the pollen to other trees and when fertilized the trees form fruits or nuts and seeds.

The hardwood/softwood terminology does make some sense. Evergreens do tend to be less dense than deciduous trees, and therefore easier to cut, while most hardwoods tend to be more dense, and therefore sturdier. In practical terms, this denseness also means that the wood will split if you pound a nail into it. Thus you need to drill screw or bolt holes to fasten hardwood together. But structural lumber is soft and light, accepts nails easily without splitting and thus is great for general construction.

To sum up

Hardwood tend to be darker, heavier, more expensive, last several decades, naturally resistant to weather.
Softwood tend to be lighter in color, lighter weight, cheaper, last for a decade or so and can be weather resistant but needs to be treated.

Knowledge: countertop

A countertop is a horizontal work surface in kitchens or other food preparation areas, bathrooms or lavatories, and workrooms in general. It is frequently, but not only, installed upon and supported by cabinets. The surface is positioned at an ergonomic height for the user and the particular task for which it is designed. A countertop may be constructed of various materials with different attributes of functionality, durability, and aesthetics. The countertop may have built-in applicances, or accessory items relative to the intended application.

Countertops come in a variety of materials such as:

Natural stones, Silicate mineral, Wood (Hardwood & Softwood), Crafted glass, Manufactured materials (Concrete, Compressed paper or fiber, Cultured marble, High pressure laminates) and many more.

Kitchen countertop and its cabinet

Kitchen countertop and its cabinet


Wooden countertops can come in a variety of designs ranging from butcher block to joined planks to single wide stave. Wood is considered to be the most eco-friendly option when it comes to choosing a kitchen countertop as wood is a renewable resource. Wood countertops must be thoroughly cleaned and disinfected after contact with foods such as raw meat. Although the use of wooden work surfaces is prohibited in commercial food production areas in the EU, and the US Department of Agriculture advises against the use of wooden chopping boards, research by the Food Research Institute at the University of Wisconsin has shown that wooden work surfaces are no more dangerous, and in some cases safer than plastic alternatives. They have shown that while bacteria do get absorbed by the wood, they do not multiply and eventually die. While brand new plastic work surfaces are indeed easy to disinfect, once they have become heavily knife scarred they are nearly impossible to completely disinfect. This is not a problem with wooden work surfaces where the number of knife cuts made little difference.

We, at Kaltimber, produce some custom countertop with three different types of finishing (Smooth, Semi-smooth , Rustic) and two different thicknesses (2cm and 4cm). Feel free to contact us to get your personalized quote today!

Reclaim Ulin countertop

Reclaim Ulin countertop

Wood-decay fungus

Brown rot

Brown rot

A wood-decay fungus is any species of fungus that digests moist wood, causing it to rot. Some species of wood-decay fungi attack dead wood, such as brown rot, and some are parasitic and colonize living trees. Excessive moisture in wood is required for fungal colonization and proliferation. Fungi that not only grow on wood but permeate its fibrous structure and actually cause decay, are called lignicolous fungi. In nature, this process serves to break down complex molecules and return nutrients to the soil. Various lignicolous fungi consume wood in various ways; for example, some attack the carbohydrates in wood and some others decay lignin (structural materials in the support tissues of vascular plants). The rate of decay of wooden materials in various climates can be estimated by empirical models.

Wood-decay fungi can be classified according to the type of decay that they cause. The best-known types are brown rot, soft rot, and white rot. Each produce different enzymes, can degrade different plant materials, and can colonize different environmental niches.

Brown-rot fungi break down hemicellulose and cellulose that form the wood structure. In this type of decay, the wood shrinks, shows a brown discoloration, and cracks into roughly cubical pieces, a phenomenon termed cubical fracture. Brown-rot fungi of particular economic importance (3 main fungi) may attack timber in buildings. Dry rot is a generic name for certain species of brown-rot fungi.

There are very few brown rot fungi in tropical climates.

Soft-rot fungi leads to the formation of microscopic cavities inside the wood, and sometimes to a discoloration and cracking pattern similar to brown rot.

Soft-rot fungi are able to colonize conditions that are too hot, cold or wet for brown or white-rot to inhabit. They can also decompose woods with high levels of compounds that are resistant to biological attack. Bark in woody plants contains a high concentration of tannin, which is difficult for fungi to decompose, and suberin (waterproofing waxy substance) which may act as a microbial barrier.

White rots break down lignin and cellulose and commonly cause rotted wood to feel moist, soft, spongy, or stringy and appear white or yellow. There are many different enzymes that are involved in the decay of wood by white-rot fungi. White-rot fungi are grown all over the world as a source of food – for example the shiitake mushroom, which in 2003 comprised approximately 25% of total mushroom production.






Source wikipedia