Red Balau Decking & Siding — Batu Hardwood

Q: Is Red Balau the same as Batu?

Yes. Red Balau and Batu are two names for Shorea guiso . You will also see it sold as Meranti Batu, Red Selangan Batu, Selangan Batu, Membatu or Mangaris. It is a different species from Golden Balau (Yellow Balau, Bangkirai) — related, but redder, harder and easier to work.

Shop Red Balau, Batu

21 products available to order online.

Shop all products →

Red Balau — sold just as often as Batu, and botanically Shorea guiso — is the tropical hardwood people buy when they want a mahogany-looking deck that behaves. The heartwood runs russet red-brown to deep brown with the resin canals showing as fine white concentric lines on the end grain, and the grain is straight with a medium-to-fine, even texture.

It is a genuinely easy wood to build with. At 2,100 lbf on the Janka scale it is harder than Golden Balau and about three times harder than Douglas Fir, but it is far kinder to tools and fasteners than Ipe or Cumaru — Batu is one of the easiest of the dense tropical decking hardwoods to cut, drill and install. Plenty of people who have fought an Ipe deck do their next one in Batu on purpose.

What sets our Batu apart from every other hardwood we stock is the breadth of the line. This is not four deck-board sizes: it is a complete exterior package — decking from 1x4 to 2x6, 4x4 and 6x6 posts, 2x4 handrail, 2x2 balusters, 5/4x12 bullnose stair treads, 1x10 fascia, rainscreen siding, T&G paneling and edge-and-center-bead porch ceiling. One species, one color, from the joist line to the soffit.

Red Balau decking at a glance

Property	Red Balau / Batu (Shorea guiso)
Also sold as	Batu, Meranti Batu, Red Selangan Batu, Selangan Batu, Membatu, Mangaris, Alan Batu
Botanical name	Shorea guiso — family Dipterocarpaceae
Origin	Indonesia, Malaysia and the Philippines
Janka hardness	2,100 lbf — about 3× Douglas Fir and 7× Western Red Cedar
Density	850 kg/m³ (about 53 lb/ft³)
Modulus of rupture	18,400 psi
Modulus of elasticity	2,560 ×1,000 psi
Shrinkage	6.3% radial · 8.8% tangential
Natural durability	Excellent — resists rot, decay and insects with no treatment
Color	Russet red-brown to medium brown; darkens under UV, weathers to beige-grey
Grain & texture	Straight grain, medium to fine even texture
Workability	One of the easiest dense tropical hardwoods to work — much easier than Ipe or Cumaru
Drying	Dries rapidly with little degrade; we stock it kiln-dried
Warranty	25-year manufacturer warranty against rot and decay, backed by Ghent
Stocked at Ghent	19 profiles — decking, posts, rail, balusters, treads, fascia, siding, paneling, ceiling

Why Batu wins jobs

Real mahogany color

The rich, classic mahogany look without the inconsistency and maintenance headaches that come with Cambara or plain Meranti. Board-to-board color that actually matches.

The easiest to install

Dense enough to last, kind enough to work. Batu takes traditional face fastening without the fight — the single most common reason a crew switches to it after an Ipe job.

A complete package

Decking, posts, handrail, balusters, bullnose treads, fascia, rainscreen siding, paneling and porch ceiling — all one species, so the whole structure weathers together.

Durable, and warrantied

Naturally resistant to rot, decay and insects with nothing added — and covered by a 25-year manufacturer warranty against rot and decay that Ghent stands behind.

Red Balau vs Golden Balau vs Ipe

These are the three tropical hardwoods we sell the most of, and the choice between them is usually settled by color and budget rather than by performance — all three will outlast a treated-pine deck several times over.

The short version: pick Red Balau if you want the mahogany red-brown and the widest range of matching parts. Pick Golden Balau if you want the honey-gold tone. Pick Ipe if longevity is the only thing that matters and the budget will carry it.

	Red Balau (Batu)	Golden Balau	Ipe
Color	Russet red-brown, mahogany	Golden brown	Deep brown to near-black
Janka hardness	2,100 lbf	1,798 lbf	3,680 lbf
Density	850 kg/m³	930 kg/m³	1,050 kg/m³
Modulus of rupture	18,400 psi	20,950 psi	25,400 psi
Workability	Easiest of the three	Dense — pre-drill	Hardest to work
CITES Appendix II	No	No	Yes, since 2022
Cost per lineal foot	Lowest of the three	About the same as Batu	Roughly double either balau
Profiles stocked	19 — full exterior package	4 decking sizes	5 decking sizes
Left unfinished	Weathers to beige-grey	Weathers to silver-grey	Weathers to silver-grey

Fire performance

Batu has an unusually high silica content, which makes it strongly resistant to flame spread. The Batu we stock is Nova’s, and it has been fire-tested to Class A — the same flame-spread class as concrete and steel, and the same class Ipe carries.

If you are specifying into a wildland-urban-interface zone or a commercial assembly where the inspector will want paperwork, ask us for the test reports before you order — we would rather hand you the documentation up front than have you discover you need it at inspection.

Let it grey, or bring it back — repeatedly

Batu is photosensitive: it darkens under UV, then fades toward beige-grey if you leave it alone.

That is the whole maintenance story, and the good news is that it is reversible as many times as you like. A wash and a coat of penetrating oil brings the red-brown straight back — no sanding, no stripping. Owners who want the color permanently just put the deck on a one-to-three-year cycle depending on exposure.

ExoShield in Natural keeps the wood looking like fresh Batu; Black Walnut pushes it darker and holds longer in hard sun, because a heavily pigmented finish blocks more UV. Either way you are protecting the color, not the wood — Batu does not need a finish to survive.

ExoShield wood stain

Red Balau deck finished in ExoShield Natural on a pine-shaded lake deck

What we stock — the full Batu line

Decking. 5/4x6 and 5/4x6 grooved (for hidden clips), 5/4x4, 5/4x4 grooved, 1x6, 1x4, 2x4 and 2x6 for heavier framing and dock work, plus 5/4x4 T&G for covered porch floors.

Rail and structure. 4x4 and 6x6 posts, 2x4 handrail, 2x2 balusters, 5/4x12 bullnose stair treads and 1x10 fascia.

Siding, paneling and ceiling. 1x6 rainscreen siding, 1x4 T&G V2E paneling, 1x6 ECB WP4 paneling and 1x4 edge-and-center-bead porch ceiling.

Everything is all-heart, kiln-dried, and priced by the lineal foot so you order the exact tally rather than square footage you throw away. Sample boards are $5 — worth it, because red-brown reads very differently in your own light than on a screen.

What people build with Batu decking

Decks & porches

The mahogany deck people picture when they say they want a mahogany deck — without Cambara’s inconsistency.

Rainscreen & commercial cladding

Open-joint rainscreen walls and storefronts, where every reveal is on show and boards have to stay flat.

Porch ceilings & soffits

Edge-and-center-bead ceiling stock in the same species as the deck below it, so the whole porch ages as one.

Fencing & privacy screens

Board-on-board and slatted fences that stay straight — and take a stain as evenly as the deck does.

Rail, stairs & structure

Posts, handrail, balusters and bullnose treads milled to match, so nothing on the deck is a different wood.

Wet and lit environments

Dock and poolside work, and anywhere hardware, lighting and constant wetting would punish an ordinary board.

Installing Red Balau

Batu is the friendliest of the dense tropical hardwoods to install, but it is still a dense tropical hardwood.

Pre-drill and countersink for face screws, and use stainless — plain steel will stain the wood.
Or use the grooved profiles with a hidden-clip system such as the ExoDek QuickClip, which sets the gap for you and leaves no fasteners on the surface.
Gap 3/16″ to 1/4″ and keep air moving underneath. A hardwood deck that cannot dry from below will cup regardless of species.
Seal fresh end cuts with a wax-based end sealer — every cut opens end grain the mill had already sealed.
Acclimate on site for several days, stacked and stickered out of direct sun, before you fasten anything.

Working out quantities? Our calculation help and the tally calculator on each product page turn deck dimensions into a length-by-length order list.

Red Balau decking projects

Red Balau decking — common questions

Is Red Balau the same as Batu?

Yes. Red Balau and Batu are two names for Shorea guiso. You will also see it sold as Meranti Batu, Red Selangan Batu, Selangan Batu, Membatu or Mangaris. It is a different species from Golden Balau (Yellow Balau, Bangkirai) — related, but redder, harder and easier to work.

Is Red Balau real mahogany?

No, and anyone selling it as mahogany is stretching. It is a Shorea, not a Swietenia. What it does is look like mahogany — the same rich red-brown and fine even texture — with far better exterior durability than genuine mahogany at a fraction of the price.

How does Red Balau compare to Ipe?

Ipe is harder (3,680 vs 2,100 Janka), denser and longer-lived, and costs roughly double per lineal foot. Batu is redder, much easier to install, not CITES-listed, and comes in far more profiles. For a residential deck where the crew has to build rail, stairs and fascia to match, Batu usually wins on total cost and aggravation.

Red Balau or Golden Balau?

Color, mostly. Red Balau is russet red-brown; Golden Balau is honey-gold. Red Balau is harder (2,100 vs 1,798 Janka) and easier to work; Golden Balau is stiffer and stronger in bending. Prices are close. We stock samples of both — order one of each and decide in daylight.

Is Red Balau fire rated?

The Batu we stock has been fire-tested to Class A, the same flame-spread class as concrete and steel — its high silica content makes it strongly resistant to flame spread. If you are specifying into a fire zone, ask us for the test reports before you order.

Do I have to pre-drill Red Balau?

For face screws, yes — it is a dense hardwood and an undrilled screw will split or snap. That said, Batu is the most forgiving of the tropical hardwoods in this respect; crews who have wrestled Ipe find it noticeably quicker. Grooved profiles with hidden clips skip face fastening entirely.

How long does a Batu deck last?

Built above grade with proper gapping and airflow, decades — it is rated excellent for natural durability against rot and decay, with no chemical treatment to wear out. Drainage and ventilation matter more to the number than the species does.

What sizes do you stock?

Nineteen profiles: decking in 1x4, 1x6, 5/4x4, 5/4x6 (plain and grooved), 5/4x4 T&G, 2x4 and 2x6; 4x4 and 6x6 posts; 2x4 handrail; 2x2 balusters; 5/4x12 bullnose stair treads; 1x10 fascia; 1x6 rainscreen siding; 1x4 and 1x6 paneling; and 1x4 ECB porch ceiling. All kiln-dried and priced by the lineal foot.

Does Red Balau need to be sealed?

Only if you want to keep the color. Bare Batu will not rot; it fades toward beige-grey. Unlike a lot of woods, the color comes back cleanly — wash and re-oil, no sanding, as many times as you like over the life of the deck.

Is there a warranty on Red Balau decking?

Yes — 25 years against rot and decay, from the manufacturer, provided the installation guidelines are followed. Ghent stands behind it as well: if the manufacturer is ever not there to honor a claim, we will. That covers every naturally durable hardwood we sell — Red Balau, Yellow Balau, Ipe and Doju.

Can I get a sample?

Yes — $5 from any Red Balau product page. Worth doing before you commit to a whole deck in a red-brown you have only seen on a screen.

Price your Red Balau project

Send us the dimensions — deck, rail, stairs, siding, all of it — and we will come back with a length-by-length tally and a delivered price. Comparing species? See how Batu lines up against everything else we stock on our decking comparison, or read the full technical profile on the Red Balau species page.

Request a quote Talk to us