Walnut, Yellow

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Yellow walnut is a well-shaped, medium-sized tree, attaining a maximum height of 25 to 30 metres. It occurs in North Queensland rainforests around the Johnstone and Russell Rivers, Evelyn and Daintree Rivers, Bellenden Ker Range and the Atherton Tableland. Commercial availability of yellow walnut timber is currently very limited, due to enforced conservation of the rainforests in which it typically occurs. 

The heartwood of this species is pale to bright lemon yellow in colour. Sapwood is typically paler but often difficult to distinguish from the true wood, since it can occupy up to 50% of the stem radius. Grain is straight and moderately coarse, with little or no figure - although back-sawn surfaces may occasionally show figure due to earlywood/latewood ring formation.

In terms of durability, yellow walnut is a class 4 hardwood, with a maximum life expectancy of between five and seven years (aboveground and in-ground application, respectively). The sapwood (but not heartwood) of this species is readily impregnated with preservatives using commercially available procedures. Untreated sapwood is susceptible to borer attack. Yellow walnut is not resistant to termites.

Common applications of yellow walnut range from light construction (as sawn timber in general house framing, flooring, linings and mouldings) to a variety of decorative uses (plywood, furniture, joinery, turnery, carving and paneling).

Appearance

The heartwood of yellow walnut is pale to bright lemon yellow in colour. Sapwood is generally paler but often difficult to distinguish from the heartwood, especially since it can occupy up to 50% of the stem radius. Grain is straight and moderately coarse with little or no figure - although back-sawn surfaces may occasionally show figure due to earlywood/latewood cell formation into rings.

Common Applications

Common applications of yellow walnut range from decorative (plywood, furniture, joinery, turnery, carving and panelling) to light construction (as sawn timber in general house framing, flooring, linings and mouldings).

Common Form

Sawn

Workability

The hardness of yellow walnut is rated as firm (4 on a 6-class scale) in relation to indentation and ease of working with hand tools. Due to its high silica content, the timber can be abrasive to machine cutters and tools. No difficulty has been experienced with the use of standard fittings and fastenings. Yellow walnut can be bonded satisfactorily using standard glues and procedures. It will readily accept stain, polish and paint.

Origin of Timber

QLD

Readily Available

QLD

Availability - Further Information

Although relatively common in Queensland, commercial availability of yellow walnut timber is now very limited.

Availability - Further Information

Native Forest

Shrinkage

Very Low Low Medium High Very High

Tangential :

3.80%

Radial:

2.10%

Unit Movement Tangential:

0.27%

Unit Movement Radial:

0.17%

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:

F17

F14

F11

F8

F7

Density per Standard

Seasoned:

585kg/m3

Unseasoned:

770kg/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:

Modulus of Rupture - Seasoned:

Modulus of Elasticity - Unseasoned:

Modulus of Elasticity - Seasoned:

Maximum Crushing Strength - Unseasoned:

Maximum Crushing Strength - Seasoned:

Impact - Unseasoned:

Impact - Seasoned:

Toughness - Unseasoned:

Low - up to 15 Nm

Toughness - Seasoned:

Low - up to 15 Nm

Hardness - Unseasoned:

3.2

Hardness - Seasoned:

4.8

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 Susceptibility:

Susceptible

Lyctid Borer Susceptibility - Other:

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 – Door and window joinery only

Joinery

Timber joinery products offer a classic, unique and stylish touch to any interior or exterior design. The products are produced for a variety of internal applications including door and window frames, cabinetry, skirtings, mouldings and architraves. When looking to the outdoors, joinery products range from decorative eaves and posts to eye-catching railings.

Many timber species are suitable for joinery products and care should be taken in selecting the perfect timber for the particular product and its intended finish. Rare and exotic species such as Teak and Rosewood can generate pieces of outstanding beauty but material cost and availability are also important considerations.

Commercially available species like Tasmanian oak, Australian cypress, spotted gum and the like, often make the more practical choice, with the added benefit that they can be easily matched with other timber products within the building, like flooring.

Solid timber for joinery products is generally supplied as ‘clear finish grade' but ‘paint grade' options are available and these are usually comprised of a composite material like MDF or glulam.

A large number of specialist suppliers and producers offer the consumer extensive choice of profiles for all of the most common and popular joinery products. Choice is in many cases, limited only by imagination.

Cabinetry is often associated with joinery and most typically includes, cupboards, benches and other similar ‘built in' furniture. Like joinery, cabinetry is generally specified as either paint or clear finish grade and naturally for clear finish grade timbers, appearance and surface finish are critical in achieving a successful application.

 

Panelling, Interior

Internal panelling, also known as appearance boards and linings, is not just a practical means of covering one or more walls and ceilings in a building, its inclusion in a room's interior design can generate looks that are both dramatic and stylish. Internal paneling comes as either solid natural timber paneling or as sheets of engineered wood products that provide a durable and hardwearing surface for areas subject to high impact. As they typically function as appearance products they generally have no structural requirements. This guide describes the variety of panelling products available and outlines the straightforward process of installing them.

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.

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.

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