Our recycled hardwood

Every wood enthusiast can get certified 100% recycled Ulin ironwood from NaturanexA.

To ensure a fully legal and sustainable supply for both local sale and export, we carefully reclaim wood from abandoned constructions in collaboration with the Forest Ministry.

NaturanexA ensures that no wood enthusiast is left behind with incredibly reasonable pricing, thanks to its price policy, from modest home projects to hotels and nationwide wholesalers.

While NaturanexA specializes in reclaimed Ulin, our partners offers other reclaimed hardwoods such as Teak, Bangkirai, Meranti, and Kapur. Feel free to ask us for more details.

Below, we present our Ulin ironwood and the renowned Teak from our partners.

Ulin from Kalimantan is our area of expertise!

Our specialty at Naturanexa is recovering ironwood from Indonesia's Kalimantan region and transform them in building components.

Building materials including doors, windows, fence, pergola, handrail, trellis and others that can all benefit from the strength and sustainability of ironwood.
We obtain all of our wood from legitimate, reputable sources, and we use it to create high-quality, aesthetically pleasing, long-lasting building components.

Visit our products categories for more information or get in touch with us right away for a free consultation.

Details about Ulin

The wood Ulin is extraordinary. Less than 0.5mm of growth per year resulting in a wood that is incredibly thick and perfect for exterior applications. A uncommon tree native to Indonesia is called ulin. Loss of habitat is a hazard to it.

The export of this species has been declared outlawed by the governments of Indonesia and Sarawak. Smuggling in illegal goods is a serious issue. Up to a height of 625 meters, it thrives in lowland primary and secondary forests. It frequently grows along slopes and around rivers. It needs 2500–4000 mm of rainfall on average every year.

One of the strongest and heaviest timbers in the world comes from this very significant tree. Ulin trees can live for more than a thousand years. Commonly exploitable trees for commercial use can reach heights of 30 meters or over (100 feet), and their trunk diameters can reach 92 cm (36 inches).

Trade & local names: Borneo ironwood, billion, belian, biliran, Kalimantan ironwood

Found in: Indonesia, East Malaysia, Philippines

Qualities: Growth ring borders that are unclear or nonexistent. Heartwood is predominantly streak-free brown to yellow. Heartwood and sapwood have different colors. Lemony odor is barely detectable. Fresh heartwood has yellowish to green (olive) tones; after exposure, it turns dark brown to nearly black.

Density: 0.85–1.1 g/cm³

Durability: Class 1

Uses: Heavy construction, ironwood decking. The wood is highly desired for many outdoor uses due to its great resistance to bacterial, fungal, insect, and marine borer damage. It is well-known internationally for its robust construction, such as a barrier between large steel fabrications (such boilers, pressure vessels, reactors, and many others) and trailers used for transportation. In dry docks, it is widely used as a wood to separate the ship hull from the steel supporting stands. Can be applied on unfinished flooring.

Status: According to the IUCN (World Conservation Union), this area is fragile. Overexploitation of the species, primarily by illegal loggers, puts it in danger. because to its reputation among Chinese people as a coffin wood (because to its resistance to rot and insects), the timber is currently in high demand. Listed as one of the Philippines' disappearing timber species, and Sabah considers it to be virtually extinct. It only exists in National Parks in Java and Sumatra. The current state of affairs is considered a serious depletion of stands.

Teak, a partner product.

Reclaimed Tropical Hardwoods from Our Partners at Kitaru Lumberyard

Just a short drive from our main hub in Bali, our longstanding partner Kitaru Lumberyard focuses on sourcing and reclaiming high-quality tropical hardwoods from regions such as East Kalimantan and Central Java. Every piece of timber is legally obtained, fully verified, and carefully repurposed for sustainable use in a range of applications—decking, cladding, flooring, and custom joinery projects.

Explore Our Featured Wood Species

Teak (Tectona grandis)

Teak is a renowned tropical hardwood known for its rich golden-brown color, high natural oil content, and exceptional durability. Resistant to moisture, pests, and decay, it’s often used in marine construction, upscale outdoor furniture, and architectural elements. Over time, it weathers into a distinguished silver-grey tone. Native to Southeast Asia, teak remains a sustainable option due to well-managed plantations across Indonesia.

Bangkirai (Shorea laevis)

Commonly referred to as Yellow Balau, Bangkirai is a robust and dense hardwood ideal for demanding outdoor environments. Its resistance to fungi, insects, and decay makes it suitable for decking, boardwalks, and other exterior uses. With a naturally warm hue ranging from golden to deep honey, it gracefully ages into a silvery-grey patina without losing its structural resilience.

Kapur (Dryobalanops lanceolata)

Kapur is a versatile reddish-brown hardwood valued for both strength and termite resistance. Frequently used in both load-bearing and decorative roles, it works well for cladding, roofing structures, and interior floors. Its moderate density makes it easy to handle, while its resilience holds up well in exposed conditions.

Meranti (Shorea spp.)

Meranti stands out with its smooth grain and warm, inviting tones—making it a go-to for cabinetry, paneling, and high-end interiors. Though lighter in weight, it offers reliable structural integrity. Available in red, yellow, and white varieties, reclaimed Meranti combines sustainability with timeless style for refined joinery and finishing work.

To learn more or to request detailed specifications, feel free to reach out—or connect with Kitaru Lumberyard directly through this link.

Ulin Ironwood: A Closer Look at a Rare and Resilient Hardwood

Overview of Ulin Ironwood

Also known as "Bornean ironwood" or "kayu besi" in Indonesia, Ulin ironwood (Eusideroxylon zwageri) is a highly prized tropical hardwood native to Southeast Asia—most notably the rainforests of Borneo and Sumatra. Renowned for its exceptional strength, longevity, and resistance to decay, Ulin has become a favored material among builders, woodworkers, and conservation architects alike.

Where It Grows and How It Thrives

Ulin thrives in lowland rainforests across valleys, ridges, and hillsides—typically from sea level to around 625 meters in elevation. Early in life, the tree prefers some shade, but matures best with ample sunlight. As part of Southeast Asia’s primary forests, Ulin contributes to the upper canopy layer. Its slow-growing nature (about 0.058 cm of radial growth per year) is a testament to its adaptation to the competitive, nutrient-poor soils of the region.

Botanical Features

A monotypic species of the Lauraceae family, Ulin is the sole member of its genus. These evergreen giants can soar up to 50 meters (164 feet), with trunks reaching over 2 meters in diameter. Often encircled by the parasitic vine Cassytha, the trunk typically features small rounded buttresses, resembling the foot of an elephant.

The leaves are dark green, leathery, and wax-coated, measuring 14–18 cm in length. Young leaves start out reddish or yellow-red before maturing. Ulin’s flowers are pale yellow, symmetrical (actinomorphic), and hermaphroditic—pollinated primarily by insects. Its fruits are drupes, dispersed by birds, rodents, monkeys, and bats.

Notable Physical Properties

Ulin ironwood stands out for its resilience and unique characteristics:

• Incredible Durability: Ulin is naturally resistant to termites, decay, and even marine borers. It performs exceptionally well in damp environments and can last over 100 years in direct soil contact or more than 20 years in saltwater conditions.

• High Density & Hardness: This is a very dense wood with a smooth, fine texture—tough to work with, but incredibly long-lasting. Its resistance to insects adds to its structural reliability.

• Weather Resistance: Ulin withstands temperature shifts, high humidity, and even seawater corrosion. Its suitability for outdoor and marine applications is unmatched.

• Visual Appeal: With a natural sheen and subtle lemon-like scent when freshly cut, Ulin transitions over time from light brown to deep reddish-brown or even black. Its grain is usually straight but can occasionally interlock, giving it character and elegance.

Practical Uses of Ulin Wood

• Architecture & Construction: In Kalimantan and similar regions, Ulin is traditionally used to build homes—down to the roof shingles ("atap sirap"). Its durability in high-humidity zones makes it perfect for long-lasting structures.

• Maritime & Industrial Applications: Thanks to its resistance to rot and marine organisms, Ulin is widely used in shipbuilding, piers, docks, and even railway sleepers and power poles.

• Furniture & Decor: Its fine grain and polish-ready surface make Ulin a premium choice for bespoke furniture, cabinetry, and high-end woodcraft items.

• Cultural Significance: Ulin also plays an important role in local traditions—used in the making of ceremonial tools, weapons, and other symbolic items in indigenous cultures.

Conservation & Sustainability Challenges

Ulin ironwood is currently classified as “Vulnerable” on the IUCN Red List, with overharvesting and deforestation as the primary threats. Its naturally slow growth means recovery from heavy logging is difficult. Strict regulations have been introduced in Indonesia and parts of Malaysia (such as Sarawak), including export bans aimed at curbing illegal activity.

Despite these efforts, illegal logging and smuggling persist. Conservation strategies must include:

• Protected Areas: Establishing national parks and conservation zones where logging is banned is a key step toward preserving Ulin’s native populations.

• Sustainable Forestry Practices: Selective logging, replanting programs, and community-managed forests are essential in managing Ulin resources responsibly.

• Community Engagement: Involving local communities in forest stewardship ensures both economic opportunities and environmental responsibility are balanced.

Final Thoughts

Ulin ironwood is more than just a robust building material—it’s a cultural icon and ecological treasure. Its unmatched resistance to decay and its visual charm make it a premium choice across industries, but its rarity demands urgent conservation. Through better forest management, policy enforcement, and sustainable use, this remarkable hardwood can remain a part of Southeast Asia’s natural and cultural heritage for generations to come.

Learn More

For further details about Ulin ironwood and sustainable forestry, visit our website or get in touch with us. Let’s work together toward a more sustainable future for this remarkable resource.

Berikut versi yang telah direstruktur dan diolah ulang secara halus agar terdengar segar dan tidak seperti salinan langsung, namun tetap mempertahankan isi, urutan logis, dan tentunya tidak mengubah bagian daftar lokasi sesuai permintaanmu:

Mengapa Memilih Kayu Ulin Bekas?

Kayu Ulin dari Kalimantan telah lama dikenal sebagai salah satu material terbaik dalam dunia konstruksi. Kekuatan alaminya, ketahanan terhadap air serta serangan serangga menjadikannya pilihan unggul untuk berbagai kebutuhan. Sayangnya, kelangkaan pohon Ulin—yang tumbuh sangat lambat—membuat kayu ini semakin sulit diperoleh secara berkelanjutan. Kaltimber hadir sebagai solusi, menawarkan jual kayu Ulin bekas berkualitas tinggi yang 100% reclaim dari pembongkaran bangunan, sebagai alternatif yang ramah lingkungan dan tetap kuat secara struktural.

Kaltimber: Ahlinya Kayu Ulin Bekas Asli

Kami di Kaltimber fokus menyediakan kayu Ulin bekas yang benar-benar reclaimed, bukan kayu muda yang baru ditebang lalu diklaim sebagai kayu bekas. Semua produk kami berasal dari proyek pembongkaran bangunan lama, sehingga telah terbukti kuat dan awet. Layanan kami menjangkau berbagai kota besar di Indonesia:

• Jual kayu Ulin bekas Banjarmasin

• Jual kayu Ulin bekas Jogja

• Jual kayu Ulin bekas Bandung

• Jual kayu Ulin bekas Jakarta

Setiap batang kayu telah melalui proses seleksi ketat untuk memastikan kualitas maksimal. Cocok untuk kebutuhan seperti pagar kayu, lantai, hingga struktur bangunan lainnya.

Kelebihan Kayu Ulin Kalimantan

Kayu Ulin dikenal memiliki serat yang padat dan stabil, menjadikannya sangat tahan terhadap kelembapan dan gangguan hama. Itulah alasan kayu ini banyak digunakan pada bangunan yang terekspos cuaca ekstrem. Balok-balok kayu Ulin dari Kaltimber sangat cocok digunakan dalam proyek yang menuntut daya tahan tinggi dan performa jangka panjang.

Tersedia Jual Balok Kayu Ulin Bekas Jogja dan Kota Lain

Kami juga melayani jual balok kayu Ulin bekas Jogja, cocok untuk proyek konstruksi atau renovasi rumah Anda di wilayah Yogyakarta dan sekitarnya. Selain itu, kami juga menyediakan layanan jual kayu Ulin bekas Jogyakarta untuk Anda yang membutuhkan material berkualitas tinggi dengan harga terjangkau.

Solusi Hemat: Harga Kayu Ulin Bekas

Kalau Anda mempertimbangkan harga kayu Ulin per batang atau per m³, kayu bekas dari Kaltimber memberi nilai lebih. Kayu bekas kami sudah melalui proses alami pengeringan selama bertahun-tahun, sehingga stabil dan tidak mudah berubah bentuk. Dibandingkan kayu baru yang tampak lebih murah tapi berisiko tinggi, kayu reclaim menawarkan investasi yang lebih cerdas dan tahan lama.

Produk Tambahan: Minyak Perawatan & Potongan Kayu

Selain menyediakan jual kayu Ulin bekas potongan, kami juga menawarkan produk pelengkap seperti minyak kayu Ulin. Minyak ini menjaga kayu tetap awet dan tahan terhadap cuaca dan serangga. Untuk kebutuhan dalam jumlah besar, tersedia juga jual kayu Ulin bekas bongkaran yang siap kirim ke proyek Anda.

Pentingnya Memilih Sumber yang Terpercaya

Ketika membeli kayu Ulin, pastikan Anda hanya bertransaksi dengan penyedia yang terpercaya. Di Kaltimber, kami hanya menjual kayu yang benar-benar reclaim, legal, dan diperoleh secara bertanggung jawab. Hindari penawaran murah dari oknum tidak resmi yang bisa saja menjual kayu baru berkualitas rendah dengan label "bekas".

Penutup

Jika Anda membutuhkan kayu Ulin untuk proyek pembangunan atau renovasi, Kaltimber adalah pilihan terbaik. Kami menyediakan jual kayu Ulin bekas di Jakarta, Jogja, Bandung, Banjarmasin, dan kota-kota lainnya. Dengan pengalaman luas dan komitmen pada keberlanjutan, kami memberikan kayu Ulin bekas asli berkualitas tinggi dengan harga kompetitif. Lebih dari sekadar hemat biaya, Anda juga turut berkontribusi pada pelestarian lingkungan.

Hubungi kami hari ini dan dapatkan kayu Ulin reclaim terbaik untuk proyek Anda!