Gmelina Wood (Gmelina arborea): Properties, Density & Uses

What Gmelina Is

Gmelina is a fast-growing, medium-to-large deciduous hardwood of the mint family, Lamiaceae, into which it was moved from the older Verbenaceae placement 1. In India the trade knows it as gamari, gambhar or melina, and it carries a long list of other names — white teak, beechwood, yemane and, in the south, kumbil or kumizh 1. Botanically it is a hardwood, but at roughly 500 kg/m³ it is low in density and only modest in strength, so in the workshop it behaves far more like a light utility timber than a dense structural hardwood. That combination of light weight and clean peeling is exactly what makes it a workhorse of the plantation plywood trade.

Where It Grows

The accepted botanical name is Gmelina arborea Roxb., placed by Kew's Plants of the World Online in the genus Gmelina within Lamiaceae 6. Its native range runs across South and Southeast Asia — India, Nepal, Bangladesh, Sri Lanka, Myanmar, Thailand, Laos, Cambodia, Vietnam and southern China — from sea level up to about 1,500 m 1. Since the 1960s it has become one of the most important fast-growing plantation timbers in the tropics, planted well beyond its home range in Brazil, Costa Rica, West Africa (Nigeria, Sierra Leone, Ivory Coast, Gambia), Malaysia and the Philippines 1. In India much of the supply reaching the plywood line is farm-forestry material grown on short rotations rather than natural-forest timber.

Appearance and Grain

The heartwood is pale yellowish-brown to golden or ashy grey, sometimes with faint pink streaks, and shows little contrast against the light yellow to nearly white sapwood 5. The grain is usually straight but can be interlocked or wavy; the texture is medium to moderately coarse with a natural lustre, and the surface can feel slightly oily to the touch 5. The pale, even colour is a practical asset for panel work — it gives a clean, light face and core that takes paint, laminate or a clear coat without the dark streaking of many hardwoods. The name white teak reflects that pale look, though gmelina is far lighter and softer than true teak.

Weight, Density and Strength

Gmelina is a lightweight hardwood. A working average of about 500 kg/m³ (31 lb/ft³) at 12% moisture is reasonable, though published figures span a genuinely wide band: the Forest Products Laboratory reports a basic specific gravity near 0.41, Izabal Wood lists 464 kg/m³, and PROTA gives a range of 400–580 kg/m³ 124. That spread reflects real variation between fast-grown plantation stock and slower-grown material, so we present ~500 kg/m³ as a representative midpoint. Janka side hardness sits around 3,200 N (720 lbf), with the FPL sheet giving a range of 525–720 lbf at 12% moisture 1. Bending strength (modulus of rupture) is reported from about 55 to 102 MPa, dropping to roughly 50 MPa for fast-grown plantation timber, and stiffness (modulus of elasticity) runs 5.5–10.8 GPa 24. In weight terms gmelina sits just above okoume — around 500 kg/m³ against okoume's ~430 kg/m³ 3 — so a gmelina panel is modestly denser and firmer while both stay firmly in the light, easy-to-handle plywood class.

Working, Peeling and Finishing

Gmelina is an easy timber to work. It cuts cleanly with both hand and machine tools and has only a slight blunting effect on cutting edges 2. Its defining property for the panel trade is that it rotary-peels cleanly into veneer, and it also planes to a smooth finish, glues and polishes well, and holds nails and screws adequately, though pre-boring is advised for screws near edges 25. It dries fairly quickly and easily with little degrade, and once seasoned it is dimensionally stable in service — shrinkage is low and fairly even at roughly 1.2–1.5% radial and 2.4–3.5% tangential from green to 12% moisture 4. That low, balanced movement is a large part of why it makes such a reliable, flat-lying plywood core.

Durability and Treatment

Durability is where gmelina asks for care. The heartwood is moderately durable, rated moderately resistant to fungal decay with a service life around 10–15 years under favourable, covered conditions 5. Resistance to termites, however, is variable — reported from moderate to susceptible — and the pale sapwood is not durable 4. It is therefore not a species to leave untreated in ground contact or sustained outdoor exposure. The saving grace is that it takes preservative treatment readily, so for demanding or exterior end uses the sensible route is to treat it rather than rely on the natural heartwood alone 4.

The Wider Genus and Grade Variation

The genus Gmelina holds roughly 30–35 species, but G. arborea is by far the main commercial timber; the Australian white beeches (G. leichhardtii, G. fasciculiflora) are only minor cabinet and carving woods 6. The single most important thing to understand about buying gmelina is that its properties track growth rate: fast-grown plantation stock on short rotations tends to be lighter and weaker than slower-grown material, which is why published density, hardness and strength figures span such a broad range 4. For plywood that variation is manageable — it is peeled, graded and cross-laminated — but it is the reason we treat the data-sheet numbers as bands rather than fixed values.

Sustainability and Legality

Gmelina is not a conservation concern. The IUCN Red List classes it as Least Concern: the species is widespread and extensively cultivated, and what localised pressure exists comes from harvesting for the medicinal trade rather than for timber 1. Because commercial supply comes overwhelmingly from plantations and farm forestry rather than natural forest, using gmelina veneer puts no pressure on wild populations. It carries no CITES restriction, so the practical concern is ordinary proof of lawful, documented origin rather than any species-level trade control.

How Cochin Wood Uses Gmelina

At Cochin Wood Industries we use gmelina as a light, pale, plantation-sourced plywood core. As a fast-grown South-Indian farm-forestry hardwood — melina or gamari — it peels clean, dries flat and stays dimensionally stable, which makes it a dependable, economical core beneath a range of faces. Its pale colour and low movement suit it to commercial plywood and general utility panels, and it sits naturally alongside eucalyptus in our plantation-hardwood core mix — gmelina lighter and easier to peel, eucalyptus denser and stiffer. Because its durability is only moderate, we treat it as an interior and packing-grade core rather than an exterior-exposure species. To compare it against the rest of our range see all species in the encyclopedia and the full catalogue for what we manufacture and stock.