MERANTI, LIGHT RED/ RED SERAYA
INTRODUCTION
The Standard Malaysian Name for the pink-red and lightweight timber of the genus Shorea (Dipterocarpaceae). Vernacular names used include majau (Sabah), meranti (Peninsular Malaysia and Sarawak) with various epithets, seraya batu (Sabah) with various epithets, red seraya (Sabah) and various other local names too numerous to list here. Major species include S. acuminata (partly), S. dasyphylla, S. hemsleyana, S. johorensis, S. lepidota, S. leprosula, S. ovalis, S. palembanica, S. parvifolia, S. platycarpa (partly) and S. teysmanniana. The sapwood is lighter in colour, usually greyish and distinct from the heartwood, which is light pink to light red or light brown.
Also known as Light Red Meranti (Brunei); Meranti merah, Meranti merah muda, Seraya merah (Indonesia); Almon, Light red lauan, Light Red Philippine Mahogany, Mayapis, Tangile and Urung (Philippines); Saya and Saya-khao (Thailand).
DENSITY
This is a Light Hardwood with a density of 385-755 kg/m3 air dry.
NATURAL DURABILITY
Light red meranti (LRM) is not durable when used in contact with the ground or in exposed conditions. The heartwood is resistant to fungal attacks but not resistant to termite attacks. However, the sapwood of the timber is liable to attack by drywood termites which may subsequently spread to the heartwood. Almost all the species of LRM are resistant to powder-post beetle attacks (Menon, 1957). The standard graveyard tests conducted at the Forest Research Institute Malaysia (FRIM) have indicated that the average service life of this timber is less than two years and is therefore classified as not durable (Jackson, 1965; Dahlan & Tam, in press). However, this classification applies to the less durable species like S. ovalis, S. leprosula and S. teysmanniana. For S. acuminata, S. parvifolia and S. hemsleyana, the average service life is more than two years and are classified as moderately durable. Similar tests done at Princess Risborough (U.K.) showed that it is moderately durable with a service life of 15-25 years when in contact with the ground (Anon., 1975). It was reported by Burgess (1966) that the timber is highly susceptible to attack by marine borers.
PRESERVATIVE TREATMENT
The LRM is generally resistant to preservative impregnation.
TEXTURE
Texture is coarse but even, with interlocked grain.
STRENGTH PROPERTIES
The timber falls into Strength Group C (Engku, 1988b) or SG 6 (MS 544:Part 2:2001).
| Strength Properties of Dark Red 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. acuminata | Green | 10,500 | 54 | 27.4 | 2.41 | 6.3 |
| S. hemsleyana | Green | 13,200 | 68 | 37.0 | - | 7.7 |
| Air dry | 13,400 | 77 | 42.7 | - | 11.0 | |
| S. leprosula | Green | 11,400 | 53 | 29.0 | 2.39 | 6.4 |
| Air dry | 13,600 | 75 | 41.4 | 2.51 | 6.8 | |
| S. parvifolia | Green | 9,300 | 50 | 25.6 | 2.00 | 5.9 |
| Air dry | 10,200 | 63 | 34.5 | 2.41 | 6.5 | |
MACHINING PROPERTIES
It is easy to saw and work and gives a smooth planed surface.
| Machining Properties of LRM | |||||||||
|---|---|---|---|---|---|---|---|---|---|
| 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. acuminata | Green | easy | easy | easy | smooth | easy | smooth | - | - |
| Air dry | easy | easy | easy | smooth | easy | smooth | easy | moderately smooth | |
| S. hemsleyana | easy | easy | easy | smooth | easy | smooth | - | - | |
| Air dry | easy | easy | easy | smooth | easy | rough | easy | smooth | |
| S. leprosula | easy | easy | easy | smooth | easy | smooth | - | - | |
| Air dry | easy | easy | easy | smooth | easy | moderately smooth | easy | smooth | |
| S. parvifolia | easy | easy | easy | smooth | easy | rough | - | - | |
| Air dry | easy | easy | easy | smooth | easy | rough | easy | moderately smooth | |
| S. teysmanniana | easy | easy | easy | moderately smooth | easy | rough | - | - | |
| Air dry | easy | easy | easy | smooth | easy | smooth | easy | smooth | |
NAILING PROPERTY
The nailing property of most species tested is good, except for S. hemsleyana, which is rated as poor.
AIR DRYING
The seasoning properties of some species tested are summarised below:
| Species | Time to air dry (months) | Remarks | ||
|---|---|---|---|---|
| 13 mm thick boards | 25 mm thick boards | 38 mm thick boards | ||
| S. hemsleyana | 2.5 | 2 | 5 | Moderately slow drying; free from all seasoning defects. |
| S. leprosula | 2 | 3.5 | 4 | Fairly fast drying; free from seasoning defects. |
| S. parvifolia | 2 | 3.5 | 4 | Fairly fast drying; free from seasoning defects. |
| S. teysmanniana | - | 4.5 | - | Moderately slow drying; slight bowing and twist. |
KILN-DRYING
Kiln Schedule F is recommended. The timber dries rapidly without degrade. 25 mm thick boards take about 6 days to kiln-dry from 50 to 10% moisture content, while 50 mm thick boards will require about 20 days.
| Kiln Schedule F | |||||
|---|---|---|---|---|---|
| Moisture Content (%) | Temperature (Dry Bulb) | Temperature (Wet Bulb) | Relative Humidity (%) (approx.) | ||
| °F | °C | °F | °C | ||
| Green | 120 | 48.5 | 111 | 44.0 | 75 |
| 60 | 120 | 48.5 | 109 | 43.0 | 70 |
| 40 | 125 | 51.5 | 109 | 43.0 | 60 |
| 30 | 130 | 54.5 | 109 | 43.0 | 50 |
| 25 | 140 | 60.0 | 115 | 46.0 | 45 |
| 20 | 155 | 68.0 | 124 | 51.0 | 40 |
| 10 | 170 | 76.5 | 136 | 58.0 | 40 |
SHRINKAGE
The shrinkage of some species tested are summarised below:
| Species | Shrinkage (%) (Green to air dry) | Remarks | |
|---|---|---|---|
| Radial | Tangential | ||
| S. hemsleyana | 1.9 | 5.4 | High shrinkage, especially in the tangential direction. |
| S. leprosula | 2.1 | 5 | High shrinkage, especially in the tangential direction. |
| S. parvifolia | 1.5 | 4.8 | High shrinkage, especially in the tangential direction. |
| S. teysmanniana | 1.6 | 7.4 | Very high tangential shrinkage. |
DEFECTS
The presence of brittle heart is more severe and wide spread in LRM than in dark red meranti. The defect is often accompanied by advanced stages of rot resulting in hollow cores in old and over-matured trees. It can be readily identified on the sawn end of the affected part, which is rough and irregular in outline. The frequent transverse fracture of the fibre on the sawn surface is further evidence of its presence. LRM timbers are liable to attack by 'shot-hole' and 'pin-hole' beetles and in some cases it can be quite severe.
USES
The timber is very popular as a general utility timber, being suitable for furniture, interior finishing, panelling, partitioning, mouldings, skirtings, decorative works, joinery, shop and office fittings, staircase (angle blocks, rough brackets, baluster, balustrade, handrail and sprandrel framing), flooring, decking, posts, beams, joists, rafters, door and window frames and sills, pallets (expendable type), tool handles (non-impact), vehicle bodies (planking), ship and boat building (general planking), ornamental items, cooling tower (non-structural members), plywood and light construction works.
REFERENCES
- Anon. 1975. The Natural Durability Classification of Timber. Tech. Note No. 40, Princess Risborough Lab., U.K
- Burgess, P. F. 1966. Timbers of Sabah. Sabah For. Rec. No. 6.
- Choo, K. T. & Lim, S. C. 1983. Malaysian Timbers - Light Red Meranti. Malaysian Forest Service Trade Leaflet No. 75. The Malaysian Timber Industry Board and Forest Research Institute Malaysia, Kuala Lumpur. 11 pp.
- Engku Abdul Rahman Chik. 1998b. Basic and Grade Stresses for Strength Groups of Malaysian Timbers. Malayan Forest ServiceTrade Leaflet No. 38. The Malaysian Timber Industry Board and Forest Research Institute Malaysia, Kuala Lumpur. 13 pp.
- Jackson, W. F. 1965. The Durability of Malayan Timbers. Mal. For. Ser. Trade Leaflet No. 28.
- Menon, K. D. 1957. Susceptibility of Commercial Species of Malayan Timbers to Powder-post Beetle Attack. Mal. For. Ser. Trade Leaflet No. 27.
- Menon, P. K. B. 1986. Uses of Some Malaysian Timbers. Revised by Lim, S. C. Timber Trade Leaflet No. 31. The Malaysian Timber Industry Board and Forest Research Institute Malaysia, Kuala Lumpur. 48 pp.
- Mohd. Dahlan Jantan & Tam, M. K. Natural Durability of Some Malaysian Timbers by Stake Tests. In press.
- MS 544:Part 2:2001. Code of Practice for the Structural Use of Timber: Permissible Stress Design of Solid Timber.
- Wong, T. M. 1982. A Dictionary of Malaysian Timbers. Revised by Lim, S. C. & Chung, R. C. K. Malayan Forest Records No. 30. Forest Research Institute Malaysia, Kuala Lumpur. 201 pp.