Project Description
Grey Box
Other Names
Gum-topped Box, Eucalyptus Microcarpa, Eucalyptus Woollsiana, Eucalyptus Hemiphloia
Grey box is a highly durable Australian hardwood often used for heavy construction applications and flooring.
Grey box is a tough, highly durable medium-sized Australian hardwood. It originates from the central and north coast districts of New South Wales and southern Queensland. Grey box, Eucalyptus woollsiana also occurs in parts of Victoria and South Australia.
Its heartwood is a pale, yellowish brown with the sapwood paler in appearance. It has a fine, even texture and usually features an interlocked grain. Gum veins are rarely present.
Grey box is a highly dense species, so it is quite difficult to work. It can be painted, stained and polished. Any machining or surface preparation should be done immediately prior to gluing. It is slow to dry but generally will not develop any surface checking.
Grey box is used for heavy construction, flooring, round timber wharfage, sleepers and shipbuilding.
It is mainly available in the areas in which it grows.
Shrinkage
| Very Low | Low | Medium | High | Very High | |
|---|---|---|---|---|---|
| Tangential | 7.40% | ||||
| Radial | 3.30% | ||||
| Unit Movement Tangential | 0.43% | ||||
| Unit Movement Radial | 0.23% |
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 | F34 | F27 | F22 | F17 | F14 |
Density per Standard
| Seasoned | 1105kg/m3 |
| Unseasoned | 1230kg/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 | 98 |
| Modulus of Rupture – Seasoned | 143 |
| Modulus of Elasticity – Unseasoned | 13 |
| Modulus of Elasticity – Seasoned | 16 |
| Maximum Crushing Strength – Unseasoned | 50 |
| Maximum Crushing Strength – Seasoned | 78 |
| Impact – Unseasoned | 19 |
| Impact – Seasoned | 15 |
| Toughness – Unseasoned | |
| Toughness – Seasoned | |
| Hardness – Unseasoned | 11 |
| Hardness – Seasoned | 15 |
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 Susceptibilitiy | Susceptible |
| Lyctid Borer Susceptibility – Other | |
| Termite Resistance | Resistant |
Fire Properties
| Critical Radiance Flux – Lower | 2.2 and < 4.5 |
| Critical Radiance Flux – Higher | ≥ 4.5 |
| Smoke Development Rate | < 750 |
| Average Specific Extinction Area | < 250 |
| Bushfire Resistance | BAL 12.5 and 19 – All AS3959 required applications |
| Botanical Name | Eucalyptus moluccana |
| Preferred Common Name | Grey Box |
| Species Type | Hardwood |
Appearance
Grey box has heartwood that is a pale, yellowish brown with the sapwood paler in appearance. It has a fine, even texture and usually features an interlocked grain. Gum veins are rarely present.
Grey box is very similar in appearance to coast grey box.
Common Applications
Tough and highly durable, grey box is mainly used for heavy engineering construction and flooring.
It is also used for cladding, bridges, wharves, shipbuilding, piles, poles and sleepers. Grey box is also an excellent fuel wood.
Common Form
Sawn
Workability
Grey box is a highly dense species so it is quite difficult to work. It can be painted, stained and polished. Any machining or surface preparation should be done immediately prior to gluing. It is slow to dry but generally will not develop any surface checking.
Origin of Timber
NSW
Readily Available
NSW
Availability – Further Information
Grey box is mainly available around the areas in which it grows. It is primarily available as flooring and construction material. Check with local suppliers for further information.
Native Forest.
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.