Mahogany, Red
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Other Names
Red Stringybark, Daintree Stringybark (Qld), Red Messmate (Qld), Eucalyptus resinifera
Red mahogany is an Australian hardwood with a fine grain and stunning red colouring used for engineering applications, construction, furniture and turnery.
Red mahogany is a hardwood with a fine grain and attractive red colouring. It is a versatile wood suitable for engineering applications and for use in construction. Due to its figuring, it is prized for furniture and turning. Red mahogany has become a prestigious timber owing to its durability, termite resistance and distinctive colouring.
Different species of red mahogany grow in different regions of Queensland, New Guinea and Irian Jaya. E. resinifera occurs from Jervis Bay in New South Wales to Coen in Queensland. E. pellita occurs from north of Townsville to Iron Range on Cape York Peninsula and through areas from Gladstone in Queensland to southern coastal New South Wales.
Trees of this species reach a height of 40-45m with 1-1.5m trunk diameter. The bark is fibrous, shallow to coarsely fissured, and persists on even the small branches. Different species have differently coloured bark; E. resinifera beinggreyish to reddish-brown and E. pellita being reddish-brown to brown.
Red mahogany is a dense, durable timber. The heartwood ranges from red to dark red, but sapwood is distinctively paler. The even grain is generally moderatley textured, displaying the occasional gum vein, and at times the grain is interlocked producing an attractive figure.
The density of the timber varies depending on its source; plantation grown 8.5 year-old timber has 70% of the density of natural grown timber, creating some variance in hardness.
Uses of red mahogany have included wharf and bridge construction, railway sleepers and in mining timbers. It is used for a wide range of interior and exterior purposes in general construction and can be made into indoor and outdoor furniture. Other uses include boat building, coach, vehicle and carriage building and structural plywood.
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Botanical Name
Eucalyptus pellita
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Preferred Common Name
Mahogany, Red
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Species Type
Appearance
Red mahogany is a beautiful timber, displaying a range of deep red and pale pink hues. The grain is uniform and somewhat course and can be interlocked, producing a stunning figure.Generally the heartwood is a deep, rich red in colour but it may be lighter in younger material. The timber’s sapwood is paler and clearly distinct from the heartwood. Tight gum veins, gum deposits and pinhole borer discolouration occasionally augment the appearance of the timber and pencil streak is common.
Common Applications
Red mahogany's durability, hardness and distinctive colouring make it one of the most versatile of timbers. The engineering applications of red mahogany as a sawn and round timber can be seen in wharf and bridge construction, railway sleepers, cross arms, poles, piles, mining timbers. As sawn timber for construction purposes it is used in general house framing, cladding, internal and external flooring, linings, joinery, fencing, landscaping, including use in retaining walls, although it is less ideal for use in contact with the ground.
One of its finest uses is for decorative purposes, in the manufacture of quality indoor and outdoor furniture. It is also prized for turning. Red mahogany's versatility can be seen further in its use in boat building (keel and framing components, planking), coach, vehicle and carriage building, agricultural machinery and in structural plywood.
Common Form
Sawn
Workability
For a dense timber that is very hard, red mahogany is relatively easy to work and machine with both hand and power tools. It can be satisfactorily dried using conventional air and kiln seasoning.
The heartwood is highly resistant to termites and the softwood susceptible to lyctid borer. The sapwood readily accepts preservative impregnation but penetration of heartwood is negligible using currently available commercial processes.
No difficulty has been experienced when using standard fittings and fastenings. As with most highly dense species, machining and surface preparation should be done immediately before gluing. The species holds both nails and staples well.
Finishing the timbers is possible through a range of methods. The timber accepts paint and stain and is one of the best eucalypts for painting since the wood has good resistance to surface checking. It develops a lovely finish when polished.
Origin of Timber
Readily Available
Availability - Further Information
Shrinkage
| Very Low | Low | Medium | High | Very High | |
Tangential : |
6.30% |
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Radial: |
3.90% |
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Unit Movement Tangential: |
0.34% |
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Unit Movement Radial: |
0.27% |
Strength Group 
Very High |
High |
Reasonably High |
Medium High |
Medium |
Reasonably Low |
Low |
Very Low |
|
Unseasoned: |
S1 |
S2 |
S3 |
S4 |
S5 |
S6 |
S7 |
|
|---|---|---|---|---|---|---|---|---|
Seasoned: |
SD1 |
SD2 |
SD3 |
SD4 |
SD5 |
SD6 |
SD7 |
SD8 |
Stress Grade
| Structural No. 1 |
Structural No. 2 |
Structural No. 3 |
Structural No. 4 |
Structural No. 5 |
|
Unseasoned: |
F27 |
F17 |
F14 |
F11 |
F8 |
Seasoned: |
F27 |
F22 |
F17 |
F14 |
F11 |
Density per Standard
Seasoned: |
950kg/m3 |
|---|---|
Unseasoned: |
1200kg/m3 |
Joint Group
Very High |
High |
Reasonably High |
Medium |
Low |
Very Low |
|
Unseasoned: |
J1 |
J2 |
J3 |
J4 |
J5 |
J6 |
|---|---|---|---|---|---|---|
Seasoned: |
JD1 |
JD2 |
JD3 |
JD4 |
JD5 |
JD6 |
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: |
90 |
|---|---|
Modulus of Rupture - Seasoned: |
138 |
Modulus of Elasticity - Unseasoned: |
14 |
Modulus of Elasticity - Seasoned: |
17 |
Maximum Crushing Strength - Unseasoned: |
52 |
Maximum Crushing Strength - Seasoned: |
76 |
Impact - Unseasoned: |
16 |
Impact - Seasoned: |
16 |
Toughness - Unseasoned: |
Medium - 15 - 24 Nm |
Toughness - Seasoned: |
Medium - 15 - 24 Nm |
Hardness - Unseasoned: |
9.0 |
Hardness - Seasoned: |
12 |
Durability
| Low | Moderate | Reasonably High | High | |
| (0 - 5 yrs) | (5 - 15 yrs) | (15 - 25 yrs) | (more than 25 yrs) | |
In-Ground: |
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| (0 - 7 yrs) | (7 - 15 yrs) | (15 - 40 yrs) | (More than 40 yrs) | |
Above ground: |
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| (0 - 20 yrs, usually < 5) | (21 - 40 yrs) | (41 - 64 yrs) | (More than 60 yrs) | |
Marine Borer Resistance: |
Lyctid Borer Susceptibility: |
Susceptible |
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Lyctid Borer Susceptibility - Other: |
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Termite Resistance: |
Resistant |
Fire Properties
| 0 | 1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 | 9 | 10 | |
EFH Spread-of-Flame Index: |
|||||||||||
EFH Smoke-Developed Index: |
Critical Radiance Flux - Lower: |
>2.2 and <4.5 |
|---|---|
Critical Radiance Flux - Higher: |
≥4.5 |
Smoke Development Rate: |
<750 |
| 1 - non-combustible | 2 - reasonably non-combustible | 3 - slightly combustible | 4 - combustible | |
Fire Properties Group |
Average Specific Extinction Area: |
<250 |
|---|---|
Bushfire Resistance: |
BAL 12.5 and 19 – All AS3959 required applications |
Fencing
The inherent appeal and strength of timber makes it the obvious choice for fencing. Timber fencing not only provides a natural look in keeping with the outdoor environment but it also enables the construction of a long lasting, durable property boundary. Fences come in many forms including the traditional paling, picket, post and railing styles. Most rely on a structural frame of posts embedded into the ground and two or more rails spanning between the posts. The ultimate selection of a suitable fence type or style is determined by application and aesthetics. A fence can serve a variety of purposes, including the provision of security, privacy and safety in addition to defining property boundaries. Specification for durability is important, especially for posts, given their exposure to high moisture in the ground.
This section provides an overview to best practice methods in specifying, installing and finishing a timber fence.
Mouldings
Timber mouldings add style, class and an elegant touch to any interior, offering a depth of beauty and warmth in a way only wood can. From period times to those more contemporary, timber mouldings have graced the most stylish and chic of interiors, decorating furniture, doors and windows. Decorative mouldings such as architraves, skirtings, cornices and ceiling roses remain an ever popular choice for designers seeking a finished result of beauty, style and quality. Like all timber products, mouldings are extremely versatile and durable, enhancing the aesthetics of any interior and functioning as the perfect finishing touch for designs with a focus on beauty and splendour.
Mouldings can be created from any commercially available species of timber and the moisture resistant wood product, MDF, is also a popular choice. When it comes to style and design, the sky is the limit with many suppliers offering custom matching to existing mouldings, as well as efficient supply of those that are individually designed. Installation is a breeze, with the majority of mouldings easily attached with a reputable wood adhesive. Finishes can be tailored by design requirements and the preferences of the end user, with mouldings commonly being both stained and/or painted.
Retaining Walls (Landscaping)
The natural appeal, strength and versatility of timber makes it an ideal choice for retaining wall landscaping applications.
Retaining wall systems include cantilevered round or sawn timber, mass wall and crib wall construction. Walls up to one metre in height follow a basic design and can usually be constructed using standard proprietary wall systems. An engineer will be required to plan and design walls greater than one metre, including the footings and drainage.
Drainage of retaining walls is a critical factor in influencing the long term stability of the wall and should thus form a significant part of the design and planning process.
Regular care and maintenance of retaining walls is essential in ensuring the long-term stability and safety of the structure.
Cladding, External
No other cladding material can offer the design freedom, ease of handling, range and natural beauty of timber. Timber cladding can create a building to suit almost any environment, taste or style.
Timber cladding has an inbuilt flexibility that provides natural advantages on sites subject to high winds, extreme climate, highly reactive soils, subsidence or earth tremors. And unlike masonry and other rigid materials, the natural resilience and high strength to weight ratio of timber enables it to withstand far greater stresses and movement.
Modern finishes give a long lasting and attractive appearance to timber cladding and can be used to change the colour and style of the building, making it a versatile material that will keep pace with changing tastes and fashions.
Structural Timber Poles
Timber pole construction is typically utilised to provide support for gravity loads and resistance against lateral forces. The natural appeal of timber ensures that its role is not purely structural however, with timber poles complimenting architectural designs aimed at harmonisation with the natural environment. The small number of footings required in pole frame construction also ensures minimal disturbances to the site.
With a double bearer system, poles can be spaced further apart than is usual, creating a more spacious building interior, that allows greater interior design flexibility. While poles are usually placed in a grid like system this is not compulsory and the flexibility of the application means the system can cope with a wide variety of designs, enabling designers to take full advantage of beautiful outlooks.
This article provides a comprehensive overview of the process involved in specifying, designing and constructing a solid timber pole construction.
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.
Timber flooring is a timeless product, offering a warmth and natural beauty largely unmatched by other flooring options. This article provides an overview of the installation of solid timber strip flooring over bearers and joists, timber based sheet flooring products and concrete slabs. Timber flooring is typically supplied as either solid timber or laminated wood products, made from layers of bonded timber. It fits together with a tongue and groove joint and once in place, is sanded and finished. There is a wide variety of species to select flooring from and the right species for a given application will be dependent on numerous factors. Information relating to species selection, environmental assessment, finish selection and recommended maintenance routines are all provided in this section.
