Terap


INTRODUCTION

The Standard Malaysian Name for the timber of the lighter species of Artocarpus spp. and Parartocarpus spp. (Moraceae). Vernacular names applied include terap (Peninsular Malaysia, Sabah and Sarawak) with various epithets, ara berteh (Peninsular Malaysia), miku (Peninsular Malaysia), paliu (Sabah), sukun (Peninsular Malaysia), timadang (Sabah) and timbangan (Sabah). Major species include Artocarpus altilis, A. elasticus, A. lowii, A. odoratissima, A. scortechinii, A. tamaran, A. teysmannii, Parartocarpus bracteatus and P. venenosus. The sapwood, except for some rare cases, is generally not differentiated from the heartwood, which is yellow to light yellow-brown. Occasionally, a dark brown heartwood with an orange tinge is developed, in which case, the sapwood is distinct.

Also known as Terap (Brunei); Kulu (Fiji); Aini and Chaplash (India); Pudu, Terap, Teureup and Upas (Indonesia); Taung-peinne (Myanmar); Antipolo and Malanangka (Philippines); Asina (Samoa Islands); and Hom, Ka-ok and Mai Hom (Thailand).


DENSITY

The timber is a Light Hardwood with a density of 400-560 kg/m3 air dry.


NATURAL DURABILITY

Graveyard tests on A. scortechinii, P. bracteatus and A. elasticus indicated that terap is generally perishable in contact with the ground in Peninsular Malaysia. All the test sticks of P. bracteatus and 63% of the A. scortechinii specimens were destroyed within a year, and 4% remained after 2 years (Burgess, 1979). The average service life of A. scortechinii, P. bracteatus and A. elasticus are 1.7, 1.4 and 1.1 years respectively under natural conditions. The timber is therefore classified as not durable under Malaysian conditions (Jackson, 1965).


PRESERVATIVE TREATMENT

Terap is classified as moderately difficult to treat with preservatives. 


TEXTURE

Texture is moderately coarse to coarse.


STRENGTH PROPERTIES

The timber falls into Strength Group C (Engku, 1988b) or SG6 (MS 544:Part 2:2001).


Strength Properties of Terap

Species

Test Condition

Modulus of Elasticity(MPa)

Modulus of Rupture(MPa)

Compression parallel to grain (MPa)

Compression perpendicular to grain (MPa)

Shear Strength (MPa)

P. bracteatus

Green

10,300

45

22.8

2.41

6.1

Air dry

12,000

68

34.8

3.17

9.2

A. scortechinii

Green

9,900

57

29.9

2.97

7.0

Air dry

10,300

67

35.0

3.03

9.2


MACHINING PROPERTIES

The timber is generally easy to resaw and cross-cut except for the air dry material of Parartocarpus, which is slightly difficult. Planing is easy, again with the exception of air dry Parartocarpus, which is slightly difficult. The planed surface is smooth on the tangential side but rough on the radial side due to picking up of grain.


Machining Properties of Terap

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

A. scortechinii

Green

easy

easy

easy

tangential: smooth, radial: rough due to grain pick-up

easy

rough

-

-

Air dry

easy

easy

easy

tangential: smooth, radial: rough due to grain pick-up

easy

rough

easy

rough

P. venenosus

Green

easy

easy

easy

Tangential: smooth, radial: rough due to grain pick-up

easy

smooth

-

-

Air dry

slightly difficult

slightly difficult

slightly difficult

rough due to grain pick-up

easy

rough

easy

rough


NAILING PROPERTY

The nailing property is rated as good.


AIR DRYING

The seasoning properties of some species tested are summarised below: 

Species

Time to air dry (months )

Remarks

13 mm
thick boards

38 mm thick boards

A. elasticus

1

2.5 

Very fast drying; no defects except for stains by fungi.

A. scortechinii

3

4

Fairly slow drying; slight bowing, cupping and checking.

P. venenosus

3.5

5

Fairly slow drying; slight bowing, cupping, twisting and checking.














SHRINKAGE

The shrinkage of terap is summarised below: 

Species

Shrinkage (%) (Green to air dry)

Remarks

Radial

Tangential

A. elasticus

1.5

2.9 

Fairly high shrinkage.

A. scortechinii

1.6

3.9

High shrinkage.

P. venenosus

2

4.4

Very high shrinkage.

 

 

 

 

DEFECTS

Specimens of Artocarpus and Parartocarpus were found to be attacked by dry wood termites, pin-hole beetles and blue stain fungal infestation. A certain degree of brittle heart were also found to occur in the specimens of terap.


USES

The timber is suitable for light construction, posts, beams, joists, rafters, flooring, plywood, packing boxes and crates, wooden pallets (expendable type), non-striking tool handles, pattern making, panelling, mouldings and furniture.


REFERENCES

  1. Burgess, H. J. 1979. The Timbers of Keledang and Terap. Malaysian Forest Service Trade Leaflet No. 24. The Malaysian Timber Industry Board, Kuala Lumpur.
  2. Engku Abdul Rahman Chik. 1988b. Basic And Grade Stresses For Some Malaysian Timbers. Malayan Forest Service Trade Leaflet No. 38. The Malaysian Timber Industry Board And Forest Research Institute Malaysia, Kuala Lumpur. 13 pp.
  3. Jackson, W. F. 1965. The Durability of Malayan Timbers. Malaysian Forest Service Trade Leaflet No. 28. The Malaysian Timber Industry Board, Kuala Lumpur.
  4. 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.
  5. MS 544: Part 2: 2001: Code Of Practice For Structural Use Of Timber. Permissible Stress Design of Solid Timber.
  6. Tan, Y. E. & Lim, S. C. 1989. Malaysian Timbers - Terap. Timber Trade Leaflet No. 109. The Malaysian Timber Industry Board and Forest Research Institute Malaysia, Kuala Lumpur. 10 pp.  
  7. Wong, T. M. 1982. A Dictionary of Malaysian Timbers. Revised by Lim, S. C. & Chung, R. C. K. Malayan Forest Record No. 30. Forest Research Institute Malaysia Kuala Lumpur. 201 pp.