White Meranti
White Meranti Wood: Versatile and Durable for Medium Construction
Introduction
White Meranti wood, derived from the Anthoshorea group of Shorea species, is a highly versatile wood used widely across Malaysia and beyond. Known for its durability and moderate hardness, this wood is often referred to by various local names such as meranti in Peninsular Malaysia and Sarawak, and melapi in Sabah. It is an excellent choice for light to medium construction due to its balance of strength, durability, and ease of working.
Key Characteristics
- Density: White Meranti is a Light Hardwood with a density ranging from 495-995 kg/m³ air dry, making it suitable for a wide variety of structural applications.
- Natural Durability: The wood is classified as moderately durable and performs well in Malaysian conditions. It is, however, susceptible to pinhole borer and blue stain infections if not adequately treated or ventilated.
- Texture & Grain: The wood has a moderately coarse texture with shallowly interlocked grain, giving it both durability and aesthetic appeal.
Strength Properties
White Meranti timber belongs to Strength Group C, ensuring reliable performance for medium-level structural uses. Its moderate strength and durability make it suitable for various construction applications.
Applications
White Meranti wood is highly adaptable and used for a range of light to medium construction purposes:
- Construction: Ideal for posts, beams, joists, and rafters in both indoor and outdoor settings.
- Flooring & Decking: Suitable for residential and light commercial flooring, as well as decking.
- Furniture: Frequently used for creating durable, aesthetically pleasing furniture.
- Plywood & Shipbuilding: The timber’s workability makes it a favored choice for plywood and for building ships and boats.
Drying & Machining Properties
- Air Drying: White Meranti seasons at a moderate rate, with 13 mm thick boards taking about 2-3 months to air dry, while 38 mm boards take 5 months. Kiln drying is recommended for faster results.
- Machining: The wood is relatively easy to machine, particularly in the green state. It is easy to plane, resaw, and cross-cut, although in the air-dried state, it can become slightly more difficult.
Nailing & Shrinkage
- Nailing: The nailing property of White Meranti varies from good to poor, depending on the species.
- Shrinkage: The wood exhibits moderate shrinkage with tangential shrinkage ranging from 2.7% to 3%, ensuring dimensional stability.
Conclusion
White Meranti wood is a durable and versatile choice for light to medium construction, offering strength, ease of use, and aesthetic appeal. Whether for furniture, flooring, or construction, White Meranti delivers exceptional value with its balance of workability and durability.
INTRODUCTION
The Standard Malaysian Name for the timber of the Anthoshorea group of Shorea (Dipterocarpaceae). Vernacular names applied include meranti (Peninsular Malaysia and Sarawak) with various epithets, melapi (Sabah) with various epithets and other localised names too numerous to list here. Major species include S. agami, S. assamica, S. bracteolata, S. dealbata, S. henryana, S. hypochra, S. lamellata, S. resinosa and S. roxburghii. The sapwood is white and is moderately sharply differentiated from the heartwood, which is almost white when fresh and becomes light yellow-brown on exposure.
Also known as White Meranti (Brunei); Lum-bao (Cambodia); Makai (India); Dammar putih, Dammar tenang putih, Kayu tahan and Meranti putih (Indonesia); Mai khae hom, Mai kheen fai and Mai kheen khan yon (Laos); Kyilan (Myanmar); Manggasinoro and Yellow lauan (Philippines); Dumala dun (Sri Lanka); Chan, Khiam Ka Nom, Khiem Kha Norng, Kiam Ka Nom, Phayom, Saya-khao, Sukrom and Takhian-Sai (Thailand).
DENSITY
The timber is a Light Hardwood with a density of 495-995 kg/m3 air dry.
NATURAL DURABILITY
The white meranti is classified as moderately durable under Malaysian conditions. Untreated timbers of white meranti of standard test dimensions of 50 mm x 50 mm x 600 mm were subjected to graveyard tests at the Forest Research Institute Malaysia (FRIM). The average service life for the four species of white meranti tested are respectively 2.6 years (S. bracteolata), 3.6 years (S. hypochra), 4.5 years (S. roxburghii) and 4.1 years (S. henryana). The sapwood of white meranti appears to be rather readily and rapidly attacked by ‘pin-hole’ borers after felling. The timber is not resistant to marine borer attacks even though it has high content of silica in the cells. Creosote/diesel fuel treated sleepers of white meranti (S. bracteolata) have been reported to last as long as 19 years at a colliery in Peninsular Malaysia (Thomas, 1949).
PRESERVATIVE TREATMENT
The timber is amenable to preservative treatment.
TEXTURE
Texture is moderately coarse and even, with rarely straight, usually shallowly interlocked or occasionally deeply interlocked grain.
STRENGTH PROPERTIES
The timber falls into Strength Group C (Engku, 1988b) or SG 5 (MS 544:Part 2:2001).
Strength Properties of White Meranti
Species | Test Condition | Modulus of Elasticity(MPa) | Modulus of Rupture(MPa) | Compression parallel to grain (MPa) |
Compression perpendicular to grain (MPa) |
Shear strength(MPa) |
S. bracteolata | Green | 12,700 | 63 | 33.8 | 2.6 | 6.1 |
Air dry | – | – | 44.3 | 3.9 | 9.4 | |
S. henryana |
Green | 18,400 | 109 | 61.8 | 9.4 | 14.0 |
Air dry | 19,400 | 132 | 67.1 | 11.0 | 14.2 | |
S. hypochra |
Green | 14,400 | 79 | 42.1 | 4.9 | 9.0 |
Air dry | 15,700 | 97 | 51.7 | 5.9 | 10.0 | |
S. roxburghii | Green | 10,800 | 73 | 40.4 | 5.2 | 9.0 |
Air dry | 11,500 | 90 | 47.7 | 7.0 | 10.6 |
MACHINING PROPERTIES
It is easy to slightly difficult to resaw in the green condition and slightly difficult to very difficult in the air dry condition. Cross-cutting is also easier in the green than in the air dry condition. Planing is easy to slightly difficult and the surface produced is smooth to rough.
Machining Properties of White Meranti
Species | Test Condition | Sawing | Planing | Boring | Turning | ||||
Re-sawing | Cross Cutting | Ease of planing | Quality of finish | Ease of boring | Quality of finish | Ease of turning | Quality of finish | ||
S. bracteolata | Green | slightly difficult | easy | moderately easy | rough | easy | rough | – | – |
Air dry | difficult | slightly difficult | moderately easy | rough | easy | rough | moderately easy | rough | |
S. henryana |
Green | slightly difficult | slightly difficult | easy | rough | easy | smooth | – | – |
Air dry | very difficult | very difficult | slightly difficult | rough | difficult | moderately smooth | – | – | |
S. hypochra |
Green | easy | easy | easy | smooth | easy | rough | – | – |
Air dry | slightly difficult | slightly difficult | slightly difficult | moderately smooth | moderately easy | rough | moderately difficult | rough | |
S. roxburghii | Green | easy | fairly easy | easy | smooth | easy | smooth | – | – |
Air dry | slightly difficult | slightly difficult | slightly difficult | moderately smooth | easy | rough | moderately difficult | rough |
NAILING PROPERTY
Nailing property ranges from good to poor depending on the species.
AIR DRYING
The seasoning characteristics of some species of white meranti are summarised below:
Species | Time to air dry (months) | Remarks | ||
13 mm thick boards | 25 mm thick boards | 38 mm thick boards | ||
S. assamica | – | 3.5 | – | Fairly slow drying. |
S. bracteolata | 2 | – | 3 | Fairly fast drying; slight cupping, bowing, end-checking and surface-checking, insect and fungi attacks. |
S. henryana | 3 | – | 5 | Fairly slow drying; only slight end-checks and staining. |
S. hypochra | 3 | – | 5 | Fairly slow drying; only slight splitting and staining. |
S. roxburghii | 3 | 4 | 5 | Fairly slow drying; no defects. |
KILN-DRYING
Kiln Schedule J is recommended. The timber dries rapidly without any defects. 25 mm thick boards take approximately 5 days to kiln-dry from 50 to 10% moisture content. When drying timbers of thickness above 40 mm and up to 75 mm, the relative humidity of the original drying schedule should be 5% higher in each case and for timber of thickness greater than 75 mm, the relative humidity should be increased correspondingly by 10%.
Kiln Schedule J
Moisture Content (%) | Temperature (Dry Bulb) | Temperature (Wet Bulb) | Relative Humidity (%) (approx.) | ||
� F | � C | � F | � C | ||
Green | 135 | 57.0 | 123 | 50.5 | 70 |
50 | 135 | 57.0 | 119 | 48.0 | 60 |
40 | 140 | 60.0 | 118 | 47.5 | 50 |
30 | 150 | 65.5 | 121 | 49.0 | 40 |
20 | 170 | 76.5 | 127 | 53.0 | 30 |
SHRINKAGE
The shrinkage of some species of white meranti is summarised below:
Species | Shrinkage (%) (Green to air dry) |
Remarks | |
Radial | Tangential | ||
S. assamica | 1.1 | 2.9 | Shrinkage rather high. |
S. bracteolata | 1.8 | 3.0 | Shrinkage fairly high. |
S. henryana | 1.1 | 2.6 | Shrinkage rather high. |
S. hypochra | 1.3 | 2.7 | Shrinkage rather high. |
S. roxburghii | 0.6 | 1.7 | Shrinkage fairly low. |
DEFECTS
White meranti generally contains less defects compared with other forms of merantis. The incidence of borer attacks in heartwood of the timber is quite negligible. The sapwood is rather readily and rapidly attacked by ‘pin-hole’ borers. Similar to most white coloured timbers, white meranti is also liable to blue stain infection (particularly the sapwood portion) if the timber is inadequately ventilated. Old trees of this timber may contain brittle-heart or in more serious cases, hollow-heart. Compression failures or cross-breaks are commonly associated with the brittle or hollow heart. Logs appear to split very little after felling.
USES
The timber is suitable for light to medium construction, posts, beams, joists, rafters, door and window frames and sills, planking, staircase (carriages, newel, risers, sprandrel framing, stringer, railing, tread, bullnose, round ends and winders), panelling, mouldings, partitioning, furniture, flooring, decking, railway sleepers, tool handles (non impact), disposable chopsticks, vehicle bodies (framework, floor boards and planking), ship and boat building (keels, keelsons, framework and general planking) and plywood.