Yellow Balau Decking — Golden Balau & Bangkirai

Yellow Balau — sold interchangeably as Golden Balau and Bangkirai — is a dense, naturally durable tropical hardwood from the forests of Indonesia and Malaysia, botanically Shorea laevis. It has been used for decks, docks, boardwalks and cladding for more than thirty years, and it is the species we point most homeowners toward when they want a genuine tropical hardwood deck without Ipe’s price tag.

The appeal is consistency. Balau comes out of the mill effectively knot-free, with a tight interlocking grain and an even, glossy texture, so a delivery looks like one deck rather than forty boards. It is rated durable against rot, fungal decay and insects with no treatment of any kind, which is why it holds up in oceanfront and marine work where treated pine has no business being.

Ghent stocks kiln-dried, all-heart Yellow Balau in 1x4, 1x6, 5/4x4, 5/4x6 and 5/4x6 grooved, S4S with eased edges, in even lengths from 8′ to 18′ — priced by the lineal foot, so you order the exact tally your deck needs instead of buying square footage you throw away. Live per-foot pricing is on each size above; the full technical profile lives on our Golden Balau species page.

Ipe is the benchmark and we sell plenty of it. But Ipe went onto CITES Appendix II in 2022 — every international shipment now needs export permits and source-country documentation — and both price and availability have moved with it. Yellow Balau is the first alternative we put in front of people: not CITES-listed, steadily available, and roughly half the cost per lineal foot.

On the mechanical numbers Ipe wins outright, and we won’t pretend otherwise. It is harder, denser, stronger and stiffer than anything else on a deck. The real question is whether the extra spend buys you something your deck will ever notice. A 1,798-lbf board is already about twice the hardness of pressure-treated pine — well past the point where foot traffic, patio furniture and dog claws leave a mark.

Read a shrinkage table cold and Ipe looks like the steadier board: 8.0% tangential against Balau’s 9.3%. What the table can’t tell you is how the board was sawn.

The Yellow Balau we sell is predominantly quartersawn — the growth rings run vertically through the thickness of the board rather than across its face. That puts the larger tangential movement into the thickness of the deck board, where nobody will ever see it, and leaves the smaller radial figure governing the width. And Balau’s radial shrinkage is 4.2% against Ipe’s 6.6%. Season to season, the gaps between quartersawn balau boards move less than the raw table implies. Vertical grain also resists cupping, twisting and warping — the failures that actually ruin a deck’s appearance, as opposed to a tenth of an inch of width.

Kiln drying is not optional. Balau is somewhat difficult to dry and needs careful conditioning; air-dried stock checks as it gives up moisture in service and can still be carrying insects. Kiln drying stabilizes the board, ends the checking, and kills anything living in it. Every board we ship is kiln-dried — if a supplier won’t tell you the moisture content of theirs, you have your answer.

All four profiles are all-heart, Select & Better, S4S with eased edges, kiln-dried, in even lengths from 8′ to 18′. Pricing is per lineal foot by length — build your tally on the product page and it totals the feet, the coverage and the price as you go.

• 5/4x6 — net 1″ × 5-1/2″. The standard residential decking board: about 0.46 SF of coverage per lineal foot, and the thickness most joist layouts are designed around.
• 5/4x6 grooved — the same board, milled with a groove on both edges for hidden-fastener clips. No grooving setup fee, and it sets your gap for you.
• 5/4x4 — net 1″ × 3-1/2″. Same thickness, narrower face (about 0.29 SF per LF) for tighter board lines and better behavior on curves and small landings.
• 1x6 — net 3/4″ × 5-1/2″. A lighter board for tight joist spacing, porch floors and ceilings.
• 1x4 — net 3/4″ × 3-1/2″. The refined option — more board lines per foot, and the easiest to work around obstacles.

Not sure it’s the right color for your project? Order a sample board before you commit — they’re $5, and a photograph on a screen is not a wood sample. Siding, ceiling, stair tread and other balau profiles are available on request through our custom milling.

Balau installs like the dense hardwood it is. None of this is difficult — it is just unforgiving of the shortcuts that work on softwood.

• Pre-drill and countersink every fastener. At 930 kg/m³ a screw driven straight in will split the board or snap. Use stainless-steel fasteners — plain steel will stain the wood.
• Or skip the face screws entirely. Our 5/4x6 grooved board takes a hidden-clip system such as the ExoDek QuickClip for a fastener-free surface and automatic, even gapping.
• Gap 3/16″ to 1/4″ for drainage and seasonal movement, and keep air moving underneath. A hardwood deck that can’t dry from below will cup no matter what species it is.
• Seal fresh end cuts with a wax-based end sealer. Every cut you make opens end grain that the mill had already sealed.
• Acclimate on site for several days before you fasten anything, stacked and stickered out of direct sun.
• Blade choice matters. A carbide blade with a high tooth count; expect to sharpen more often than you would on cedar.

Not sure how much you need? Our calculation help and the tally calculator on each product page turn deck dimensions into a length-by-length order list.