Pine, Slash

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Slash pine is a softwood native to south eastern United States and grown widely in plantations in northern NSW and in Queensland. It is mostly available in those states. It is used for general construction purposes, flooring, panelling and plywood; when treated with preservatives it is used for outdoor uses such as cladding and decking, fascia and barge boards; and for pergolas, fencing, retaining walls, landscaping, and playground equipment.

The heartwood of slash pine is pale reddish brown, while the sapwood is pale yellow and not clearly marked from the heartwood. The texture is relatively coarse and non-uniform, with alternating bands of late and earlywood. The grain is straight; the growth rings are prominent and the resin flows are very abundant. Knots are present in construction grade timber.

There is a distinctive difference in colour between earlywood and latewood, which results in a notable figure when back sawn. There are many resin canals, prominent as lines on dressed longitudinal surfaces, and the timber has a strong resinous odour. The resin can cause problems when working with the timber.

Slash pine is of low durability, with a life expectancy of less than seven years above ground and five below ground and it is resistant to termites. Only the sapwood can be treated with preservatives.

Appearance

The texture of slash pine is relatively coarse and non-uniform, with alternating bands of late and earlywood. The grain is straight; the growth rings are prominent and the resin flows are very abundant. Knots are present in construction grade timber. The heartwood is pale reddish brown, while the sapwood is pale yellow and not clearly marked from the heartwood.

There is a distinctive difference in colour between earlywood and latewood, which results in a notable figure when back sawn. There are many resin canals, prominent as lines on dressed longitudinal surfaces.

Common Applications

Slash pine  is used for general construction purposes, such as framing, flooring, lining, laminated beams, and joinery. When treated with preservatives it is used for external cladding and decking, and in fencing, pergolas, landscaping and playground equipment.

Common Form

Sawn

Workability

Only the sapwood of slash pine can be treated with preservatives. When dressing, sharp planer blades are needed to avoid compressing the softer earlywood and the ridged surfaces produced.
Because of deflection by latewood bands, nails tend to follow the growth rings and care is needed when using fittings and fastenings. Good results can be obtained with nail guns.

Due to the high resin content of some material and the ridge of early and latewood in dressed timber, care is required when timber is selected for finishing applications and when surfaces are prepared for painting and varnishing. Earlywood and latewood can absorb glue differently but this rarely causes problems.

Origin of Timber

NSW

Readily Available

NSW

Availability - Further Information

Plantation

Shrinkage

Very Low Low Medium High Very High

Tangential :

4.20%

Radial:

3.00%

Unit Movement Tangential:

0.29%

Unit Movement Radial:

0.20%

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:

F11

F8

F7

F5

F4

Seasoned:

F17

F14

F11

F8

F7

Density per Standard

Seasoned:

650kg/m3

Unseasoned:

850kg/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:

44

Modulus of Rupture - Seasoned:

75

Modulus of Elasticity - Unseasoned:

8

Modulus of Elasticity - Seasoned:

9.5

Maximum Crushing Strength - Unseasoned:

21

Maximum Crushing Strength - Seasoned:

42

Impact - Unseasoned:

8.0

Impact - Seasoned:

5.8

Toughness - Unseasoned:

Low - up to 15 Nm

Toughness - Seasoned:

Low - up to 15 Nm

Hardness - Unseasoned:

2.2

Hardness - Seasoned:

3.4

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:

Not Susceptible

Lyctid Borer Susceptibility - Other:

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:

For plywood ≥17mm >2.2 and <4.5

Critical Radiance Flux - Higher:

For plywood ≥17mm >2.2 and <4.5

Smoke Development Rate:

For plywood ≥17mm <750
1 - non-combustible 2 - reasonably non-combustible 3 - slightly combustible 4 - combustible

Fire Properties Group
Number:

Group Number - Other:

3 for plywood ≥6mm

Average Specific Extinction Area:

<250

Bushfire Resistance:

Not Tested

Portal Frames

Timber portal frames are one of the most favoured structural applications for commercial and industrial buildings whose functions necessitate long spans and open interiors. As a material choice, timber offers designers simplicity, speed and economy in fabrication and erection.

Timber portal frames offer a strong, sound and superior structure. Structural action is achieved through rigid connections between column and rafter at the knees, and between the individual rafter members at the ridge. These rigid joints are generally constructed using nailed plywood gussets and on occasion, with steel gussets.

From material selection to finishing, this application guide provides a comprehensive overview of the process of using timber in the specification, fabrication and erection of portal frame structures.

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.

 

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.

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.

Pergolas

Timber pergolas offer an attractive and economical way to create functional living and entertainment areas in the outdoors.  Pergolas designed with care can maximise both winter sunshine and summer shade, ensuring outdoor living is enjoyed all year round. With its natural look, durability and versatility there are few other materials that can match the advantages of timber in pergola construction.

Pergolas are typically constructed via a straightforward post and beam process, which can be attached to an existing building or form a free standing structure. A protective finishing coat will preserve the life of the pergola and a variety of paints and stains are available on the market to facilitate this.

 

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.

Framing

Lightweight timber construction typically comprises framed and braced structures to which one or more types of cladding are applied. Framing configurations can range from the closely spaced light timbers commonly seen in stud frame construction to large, more widely spaced timbers. A timber framed building can be placed on a concrete slab or on posts/poles or bearers resting on piers/stumps supported on pad footings.

Used in houses or multi-residential dwellings, lightweight timber construction offers the flexibility of a wide range of cost effective design options.

When the timber comes from sustainable sources, this construction method can be environmentally advantageous as it combines timber's low embodied energy with its capacity to store carbon.

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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