Keruing | Dipterocarpus confertus

Keruing is a hardwood native to South East Asia and used in a wide variety of internal and external applications.

Other Names: Apitong, Hagakhak, Panau, Dau, Eng, Yang, Keruwing, Kruen, Kujun, Klalar, Keroewing, Iagan,Dipterocarpus, Dipterocarpus alatus, Dipterocarpus apterus, Dipterocarpus baudii, Dipterocarpus cornutus, Dipterocarpus costulatus, Dipterocarpus crinitus, Dipterocarpus dyeri, Dipterocarpus exalatus, Dipterocarpus gracilis, Dipterocarpus gradiflorus, Dipterocarpus indicus, Dipterocarpus lowii, Dipterocarpus macrocarpus, Dipterocarpus obtusifolius, Dipterocarpus sublamellatus, Dipterocarpus turbinaturs. Dipterocarpus verrucosus, Dipterocarpus warburgii

Overview

Keruing is the name given to the timber yielded from more than 70 species of the genus Dipterocarpus. This group of large hardwoods is indigenous to South East Asia, where the species are harvested from managed forests with regeneration programs.

Across the entire species, a wide variety of heartwood hues are available, including deep-pink, orange-pink and purple-red. The most common heartwood is red-brown. Sapwood is usually lighter, sometimes with yellow or grey tinges. The wood darkens with age and features a generally straight, or shallowly interlocked grain, sometimes with a stripe figure on the radial surface. Texture varies between species from fine to coarse but is always uniform.

Keruing timber is low maintenance, hardwearing and ideal for outdoor furniture use. The wood is strong and classified as durable, making it useful for construction purposes. Other common uses include internal flooring, protected framing and boards, internal joinery and mouldings, lining, paneling and framework. Preservative-treated material is used for poles, piles, sleepers and cross-arms.  It is often used as a cheaper alternative to oak for heavy construction, decking, vehicle building and sleepers, and it is also in plywood.

Where other timbers may require curing, keruing is completely cured and ready for immediate use with no risk of leaching, bleeding or leach sap. It contains oleo-resins and will exude it onto surfaces during drying or when exposed to heat or sunshine when in use; gums may also cause problems in machining.

Properties

Shrinkage

Very Low Low Medium High Very High
Tangential:          
9.5
Radial: > 5

Strength Group

Very High High Reasonably High Medium High Medium Reasonably Low Low Very Low
Unseasoned:S1S2S3S4S5S6S7
Seasoned:SD1SD2SD3SD4SD5SD6SD7SD8

Stress Grade

Structural
No. 1
Structural
No. 2
Structural
No. 3
Structural
No. 4
Structural
No. 5
Unseasoned: F17 F14 F11 F8 F7
Seasoned: F27 F22 F17 F14 F11

Density per Standard

Unseasoned: 950 kg/m3
Seasoned: 750 kg/m3

Joint Group

Very High High Reasonably High Medium Low Very Low
Unseasoned:J1J2J3J4J5J6
Seasoned:JD1JD2JD3JD4JD5JD6

Colour

  White, yellow, pale straw to light brown Pink to pink brown Light to dark red Brown, chocolate, mottled or streaky
   

Mechanical Properties

Modulus of Rupture - Unseasoned: 64-82
Modulus of Rupture - Seasoned: 110-137
Modulus of Elasticity - Unseasoned: 12-13
Modulus of Elasticity - Seasoned: 14-16
Maximum Crushing Strength - Unseasoned: 30-35
Maximum Crushing Strength - Seasoned: 59-60
Toughness - Unseasoned: High - 25 Nm and above
Toughness - Seasoned: High - 25 Nm and above
Hardness - Unseasoned: 3.2-3.6
Hardness - Seasoned: 4.6-5.3

Durability

Low Moderate Reasonably High High
(0 - 5 yrs) (5 - 15 yrs) (15 - 25 yrs) (more than 25 yrs)
In-Ground:
(0 - 7 yrs) (7 - 15 yrs) (15 - 40 yrs) (More than 40 yrs)
Above ground:
(0 - 20 yrs, usually < 5) (21 - 40 yrs) (41 - 64 yrs) (More than 60 yrs)
Marine Borer Resistance:
Lyctid Borer Susceptibility: Susceptible
Termite Resistance: Not Resistant

Fire Properties

0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20
EFH Ignitibility:
0 1 2 3 4 5 6 7 8 9 10
EFH Spread-of-Flame Index:
EFH Smoke-Developed Index:
1 - non-combustible 2 - reasonably non-combustible 3 - slightly combustible 4 - combustible
Fire Properties Group
Number:
Group Number - Other: 3 if used on MDF or particleboard ≥12mm; veneer thickness 0.6-0.85mm
Average Specific Extinction Area: <250
Bushfire Resistance: BAL 12.5 and 19 – All AS3959 required applications

Description

Botanical Name: Dipterocarpus confertus
Preferred Common Name: Keruing
Other Names: Apitong, Hagakhak, Panau, Dau, Eng, Yang, Keruwing, Kruen, Kujun, Klalar, Keroewing, Iagan,Dipterocarpus, Dipterocarpus alatus, Dipterocarpus apterus, Dipterocarpus baudii, Dipterocarpus cornutus, Dipterocarpus costulatus, Dipterocarpus crinitus, Dipterocarpus dyeri, Dipterocarpus exalatus, Dipterocarpus gracilis, Dipterocarpus gradiflorus, Dipterocarpus indicus, Dipterocarpus lowii, Dipterocarpus macrocarpus, Dipterocarpus obtusifolius, Dipterocarpus sublamellatus, Dipterocarpus turbinaturs. Dipterocarpus verrucosus, Dipterocarpus warburgii
Species Type: Hardwood

Appearance

Across this entire species of keruing, a wide variety of heartwood hues are available, including deep-pink, orange-pink, and purple-red. The most common heartwood is red-brown. Sapwood is usually lighter, sometimes with yellow or grey tinges. The wood darkens with age and features a generally straight or shallowly interlocked grain, sometimes with a stripe figure on the radial surface. Texture varies between species from fine to coarse but is always uniform.

Common Applications

Keruing timber is strong and classified as durable, making it useful for construction purposes. Other common uses include internal flooring, protected framing and boards, internal joinery and mouldings, lining, paneling, and framework. Preservative-treated material is used for poles, piles, sleepers and cross-arms. It is often used as a cheaper alternative to oak for heavy construction, decking, vehicle building and sleepers, and it is also used in plywood.

Common Form

Sawn

Workability

Keruing may be difficult to work when dry due to the presence of both silica and resin. Sanding dust can irritate the skin. The wood nails satisfactorily but glues variably.

Where other timbers may require curing, keruing is completely cured and ready for immediate use with no risk of leaching, bleeding or leach sap. It contains oleo-resins and will exude it onto surfaces during drying or when exposed to heat or sunshine when in use; this high resin content makes it a poor base for coating. Gums may also cause problems in machining and it is unsuitable for steam bending.

Origin of Timber

Asia, SE Asia, Other-specify

Origin of Timber - Other

SE Asia, Indonesia, Malaysia, Sabab, Sarawak, Brunei, Pakistan, Philippines, India

Availability - Further Information

Keruing is occasionally imported to Australia.

Applications

  • Decking

    Timber decking creates spaces that are functional, practical and aesthetically pleasing. With the right design and care a timber deck will make a valuable addition to any home or business, creating an outdoor living space that will be enjoyed for years to come.

  • Flooring

    Whether for structural or finished flooring applications, timber offers durability, versatility and adaptability. The warmth, strength and natural beauty of timber flooring has proved enduringly popular in a wide variety of interior settings.

  • Framing

    Since people began building simple shelters, wooden framing has played an important role in shaping structures of many kinds. One of the most popular types of wooden framing is known as lightweight timber construction.

  • Internal Paneling

    Timber paneling creates interiors as warm as they are stylish. Commonly using an MDF or plywood substrate, internal timber paneling is natural and versatile and comes as either solid natural timber panels or as sheets of engineered wood products

  • Structural Timber Poles

    Timber poles are utilised in structural construction to provide support for gravity loads and resistance against lateral forces. Not only serving a structural function, timber poles provide many aesthetic benefits, with their use in construction often complementing architectural designs aimed at harmonisation with the natural environment.

  • Timber Joinery Products

    Timber joinery products offer a classic, unique and stylish touch to any interior design.

  • Timber Mouldings

    Mouldings are extremely versatile and durable, enhancing the aesthetics of any interior and functioning as the icing on the cake for designs with a focus on beauty and splendour.

  • Timber Portal Frames

    For buildings that require large spans and column free interiors, timber portal frames provide one of the most aesthetically pleasing solutions. Utilising modern engineering technology, portal frame design transforms timber into a highly effective, efficient and economical structural product. This application guide provides a comprehensive overview of the process of using timber in the specification, fabrication and erection of portal frame structures.

Case Studies

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