White Seraya as a Tabletop Timber
White seraya refers to several timber species within the Dipterocarpaceae family, notably Parashorea malaanonan, Parashorea tomentella, and Shorea contorta (formerly classified under Pentacme contorta). Sourced primarily from Indonesia, Malaysia, and the Philippines—where it often carries the local trade name Bagtikan—it is not listed in the CITES Appendices (Washington Convention 2025). According to technical documentation from CIRAD Tropix, mature logs range from 80 to 130 cm in diameter, providing ample width for large dining tables and river slab layouts. However, timber taken from large-diameter trees frequently contains ring shakes and brittleheart near the center, requiring deliberate grading before building.
Appearance, Figure, and Grain Characteristics
The heartwood ranges in color from pinkish white to light yellow or light brown with pink shades. The sapwood measures between 2 and 7 cm in thickness but is not clearly demarcated from the heartwood. The wood features a coarse texture with medium-sized, regular rays. A distinct visual marker in White seraya is the presence of more or less frequent white lines, which are longitudinal resin canals. The grain is interlocked—classified as marked—which produces a broad stripe ribbon figure when quartersawn. Slabs may also exhibit pinhole damage, as the timber can show black holes from wood borers.
Weight, Hardness, and Mechanical Strength
At 12% moisture content, White seraya has an average specific gravity of 0.62. This translates to an approximate density of 38.7 lb/ft³, or about 6.5 lb per square foot for a standard 2-inch-thick slab. It offers solid structural properties: a crushing strength of 50 MPa (about 7,250 psi), a static bending strength (modulus of rupture) of 84 MPa (about 12,180 psi), and a modulus of elasticity of 12,370 MPa (about 1,794,000 psi).
Its surface hardness is rated at 2.8 on the Monnin hardness scale. The Monnin scale is an empirical French test where higher values correspond to greater resistance to indentation (not to be confused with or converted to Janka ratings). At 2.8, White seraya is moderately soft to medium-hard, making it well suited for interior furniture, interior panelling, and mouldings, while requiring care against point-load dents under heavy daily wear.
Shrinkage, Stability, and Epoxy River Integration
Integrating natural wood with cast epoxy resin requires an understanding of dimensional movement, because cured epoxy does not expand or contract with ambient humidity changes. CIRAD Tropix records the fiber saturation point of White seraya at 28%. Total tangential shrinkage from green to oven-dry is 8.5%, while total radial shrinkage is 4.3%. This yields a tangential-to-radial shrinkage ratio (St/Sr) of 2.0, along with a volumetric shrinkage coefficient of 0.54% per 1% change in moisture content.
A ratio of 2.0 indicates an intermediate tendency toward cupping across plainsawn faces. Because volume changes by 0.54% for every percentage change in moisture, subjecting an unsealed or incompletely dried slab to seasonal humidity swings will create lateral tension against the rigid epoxy casting. To prevent bondline cleavage or check formation, the timber must be brought to indoor equilibrium before pouring and completely sealed afterward.
Drying, Machining, and Surface Preparation
White seraya dries at a normal rate with only slight risks of checking and distortion, and no known specific risk of casehardening or cell collapse. Recommended kiln schedules range from 53 °C to 62 °C (about 127 °F to 144 °F). Because distortion remains a slight hazard, proper sticker stacking is necessary during conditioning.
Tool blunting is normal, and cutting operations can be performed using ordinary or alloy steel tooling. However, the marked interlocked grain creates a persistent risk of grain tearing during surfacing and woolliness when edging boards. Cutters must be kept razor-sharp. Fastener holding is good for nailing and screwing. Because of the coarse open texture and resin canals, CIRAD Tropix notes that filling is recommended in order to obtain a smooth, high-quality finish.
Natural Durability Ratings
White seraya is not an exterior-grade timber. Heartwood resistance to decay fungi is classified as Durability class 4 (poorly durable), and it is Class S (susceptible) to dry-wood borers and termites. Heartwood treatability is Class 3 (poorly permeable). It is strictly rated for Use Class 2 (interior or under cover where dampness is occasionally possible), making indoor epoxy river tables, current furniture, and cabinetry its ideal domain.
| Property | CIRAD Tropix value | What it means / US units |
|---|---|---|
| Botanical name(s) | Parashorea malaanonan, Parashorea tomentella, Parashorea p.p., Shorea contorta, Pentacme contorta (synonymous), Shorea subgen. Pentacme p.p. | |
| Other trade names | Seraya white | |
| Colour / texture / grain | Pinkish white; texture coarse; grain interlocked; interlocked grain marked | |
| Specific gravity (12% MC) | 0.62 | about 38.7 lb/ft³; a 2-inch-thick slab weighs about 6.5 lb per sq ft |
| Monnin hardness (12% MC) | 2.8 | French hardness scale; higher = harder (not a Janka value) |
| Total tangential shrinkage | 8.5 % | green to oven-dry |
| Total radial shrinkage | 4.3 % | green to oven-dry |
| Ratio St/Sr | 2.0 | closer to 1 = less cupping tendency |
| Coefficient of volumetric shrinkage | 0.54 % per % MC | volume change per 1% change in moisture content |
| Fibre saturation point | 28 % | |
| Thermal conductivity | 0.21 W/(m·K) | |
| Crushing strength (12% MC) | 50 MPa | about 7,250 psi |
| Static bending strength (12% MC) | 84 MPa | about 12,180 psi |
| Modulus of elasticity (12% MC) | 12,370 MPa | about 1,794,000 psi |
| Decay (fungi) resistance | Durability class 4 – poorly durable | |
| Termite resistance | Class S – susceptible | |
| Dry-wood borer resistance | Class S – susceptible (risk in all the wood) | |
| Heartwood treatability | Class 3 – poorly permeable | |
| Use class from natural durability | Class 2 – inside or under cover (dampness possible) | |
| Drying | rate normal; distortion: slight risk; checking: slight risk; collapse: no known specific risk; casehardening: no known specific risk | |
| Suggested kiln program temperatures | 53–62 °C | about 127–144 °F |
| Machining | blunting normal; saw teeth: ordinary or alloy steel; cutting tools: ordinary | |
| Nailing and screwing | Good | |
| CITES status | This species is not listed in the CITES Appendices (Washington Convention 2025). Notes. The common name White Seraya is usually used for Malaysian species, Bagtikan for species from the Philippines. |
Values from the CIRAD Tropix technical sheet (average values for mature wood, 12% moisture content where noted). US-unit conversions are calculated by BigEpoxy (1 MPa = 145.04 psi; density = specific gravity × 62.43 lb/ft³).
Practical Pre-Pour Checklist
- Inspect the core of wide slabs for brittleheart or internal ring shakes common to mature logs, and cut away compromised sections.
- Examine both faces for insect damage or black holes, planning deep resin fills or stabilizing treatments where borers were active.
- Confirm the timber has reached equilibrium moisture content for your indoor climate; never pour over partially dried stock.
- Ensure wide boards were stacked flat under uniform weight to eliminate any slight cupping or twist resulting from its 2.0 shrinkage ratio.
- Surface the live edge and faces using sharp cutting knives to prevent torn grain and woolly fibers caused by interlocked growth.
- Apply a thorough seal coat or grain filler over all surfaces to manage the coarse pores and white resin canal lines prior to the main epoxy flood or river pour.
Sources
Published October 31, 2026. Sources are linked in the text.
Header image: original graphic by BigEpoxy.com.
Staff note: When inspecting wide White seraya slabs, watch for the resin canal lines (visible as fine white streaks); these can harbor localized voids that require a thin penetrating epoxy seal coat to prevent air bubbles from outgassing into your main river casting. (Source: CIRAD Tropix 7 technical sheet: White seraya.)