Project Description

WOOF Timber - Manna Gum (Viminalis)

Manna Gum

Other Names

Viminalis, Ribbon Gum, Rough-barked Manna Gum, Coast Manna Gum, White Gum

Manna gum is an Australian hardwood timber of limited commercial availability. It is suitable for applications such as flooring, joinery, paneling, furniture and general construction.

Manna gum (Viminalis) is a hardwood timber species occurring in the cooler areas of South Australia, Tasmania, Victoria and the tableland districts of New South Wales. The heartwood of the species is a pale pink or pinkish-brown colour, often with distinctive light grey streaks. Sapwood is not clearly distinguishable from the true wood. The texture of manna gum timber is medium and even with a variable grain and prominent growth rings. It is usually quarter-sawn.

Manna gum is a moderately durable timber. Its heartwood lacks natural termite resistance and untreated sapwood is susceptible to lyctid borer attack. Although moderately hard, manna gum timber is easy to work by hand or machine. It glues satisfactorily using commercially available bonding agents. Pre-drilling is recommended when nailing near the ends of boards, to avoid splitting.

Uses of manna gum timber range from general construction to internal joinery, furniture, paneling, flooring and tool handles. Potential applications include plywood.

Despite a striking appearance especially suited to more formal decorative applications, manna gum timber is relatively uncommon due to the difficulties it presents in drying. The timber is prone to internal honeycombing, surface checking and collapse during seasoning.

Shrinkage

Very Low Low Medium High Very High
Tangential 12.00%
Radial 5.10%
Unit Movement Tangential  0.34%
Unit Movement Radial  0.22%

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 F14 F11 F8 F7 F5
Seasoned F22 F17 F14 F11 F8

Density per Standard

Seasoned 780kg/m3
Unseasoned 1000kg/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 66
Modulus of Rupture – Seasoned 106
Modulus of Elasticity – Unseasoned 11
Modulus of Elasticity – Seasoned 15
Maximum Crushing Strength – Unseasoned 32
Maximum Crushing Strength – Seasoned 62
Impact – Unseasoned 15
Impact – Seasoned 15
Toughness – Unseasoned Medium – 15 – 24 Nm
Toughness – Seasoned Medium – 15 – 24 Nm
Hardness – Unseasoned 5.1
Hardness – Seasoned 5.8

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 Not Resistant

Fire Properties

Critical Radiance Flux – Lower > 2.2 and < 4.5
Critical Radiance Flux – Higher > 2.2 and < 4.5
Smoke Development Rate < 750
1 – non-combustible 2 – reasonably non-combustible 3 – slightly combustible 4 – combustible
Fire Properties Group Number .
Average Specific Extinction Area < 250
Bushfire Resistance BAL 12.5 and 19 – All AS3959 required applications
Botanical Name Eucalyptus viminalis
Preferred Common Name Manna Gum
Species Type Hardwood

Appearance

Manna gum heartwood is a pale pink or pinkish brown colour, often with distinctive light grey streaks. Sapwood is not clearly distinguishable from the true wood. The texture of manna gum timber is medium and even, with a variable grain and prominent growth rings. It is usually quarter sawn.

Common Applications

Uses of manna gum timber range from general construction to internal joinery, furniture, panelling, flooring and tool handles. Potential applications include plywood.

Despite a striking appearance especially suited to more formal decorative applications, manna gum timber is relatively uncommon due to the difficulties it presents in drying.

Workability

Although moderately hard, manna gum timber is easy to work. It glues satisfactorily using commercially available bonding agents. Pre-drilling is recommended when nailing near the ends of boards, to avoid splitting.

During seasoning, the timber is prone to degradation in the form of internal honeycombing, surface checking and collapse.

Origin of Timber

NSW

Readily Available

NSW

Availability – Further Information

Although a common eucalypt, manna gum is of limited commercial availability because of seasoning problems.

Native Forest.