Tanalised Treated Timber 75 x 150mm 4.8m
Tanalised Treated Timber 75 x 150mm 4.8m is a substantial timber section suitable for a broad range of building, landscaping and outdoor construction projects. Commonly referred to by its traditional imperial name of 6×3 timber, it combines a generous 75mm nominal thickness with a 150mm nominal width and an extended 4.8-metre length.
The thicker 75mm profile makes this product a practical choice for projects requiring a more substantial section than standard 47mm-thick timber. It can be used for garden structures, landscaping features, general frameworks, agricultural projects and other applications where robust treated timber is required.
Pressure treatment, also known as tanalising, improves the durability of the timber by helping to protect it against fungal decay and wood-destroying insects. This makes it particularly useful for outdoor projects and other applications where untreated timber could deteriorate more quickly.
Product Dimensions
The nominal dimensions of this product are:
- Thickness: 75mm
- Width: 150mm
- Length: 4.8m
- Common imperial name: 6×3
- Finish: Tanalised or pressure treated
The term 6×3 timber is the commonly used imperial trade name for this section. The stated metric size of 75 x 150mm is nominal and may not represent an exact finished measurement.
Machining, pressure treatment, moisture content and natural movement can all cause small differences in the final dimensions. Check the actual measurements before starting any project where precise finished sizing is essential.
What Is Tanalised Timber?
Tanalised timber has been treated with preservative inside a controlled pressure vessel. During this process, preservative is forced into the wood rather than simply being applied to its surface.
This treatment helps the timber resist fungal decay and attacks from wood-destroying insects. When installed correctly and used in an appropriate environment, treated timber can offer a longer service life than comparable untreated wood.
Pressure treatment does not make timber completely waterproof or remove the need for correct installation. Good drainage should be provided, prolonged contact with standing water should be avoided where possible, and newly exposed areas should be protected after cutting or drilling.
Common Uses for 6×3 Treated Timber
The substantial 75 x 150mm section makes this timber suitable for numerous professional and DIY projects. Typical uses may include:
- Heavy-duty outdoor frameworks
- Pergolas and garden structures
- Landscaping features
- Raised beds and substantial planters
- Agricultural and workshop projects
- Garden edging and timber borders
- Outdoor furniture frameworks
- General construction and joinery
- Repair and replacement projects
- Projects requiring a traditional 6×3 section
The 4.8m length provides excellent coverage for larger projects and can help reduce the number of joints required across longer runs. It may also be cut into several smaller sections, depending on the project’s measurements and design.
Because 4.8m timber can be heavy and difficult to manoeuvre, suitable lifting assistance and safe handling methods may be required. Ensure the timber is adequately supported during transport, storage, cutting and installation.
Suitability will depend on the project design, expected loads, environment and installation method. For structural or load-bearing work, confirm that the timber has the appropriate strength grade and treatment classification. Pressure-treated timber is not automatically classified as C16, C24 or another structural grade unless it is specifically marked and sold as such.
Benefits of Pressure-Treated Timber
Timber installed outdoors can be exposed to rain, moisture, changing temperatures and insects. Pressure treatment improves the timber’s resistance to these conditions and makes it suitable for many exterior applications.
The principal benefits include:
- Improved resistance to fungal decay
- Protection against wood-destroying insects
- Suitable for numerous outdoor applications
- Longer potential service life than untreated timber
- Substantial 75 x 150mm nominal section
- Extended 4.8-metre length
- Suitable for trade and DIY projects
- Can be cut to meet individual requirements
The required treatment specification will vary depending on how and where the timber will be installed. Timber intended for above-ground outdoor use may have a different treatment classification from timber suitable for direct ground contact.
If the timber will be permanently exposed to wet conditions, placed directly against soil or used in a particularly demanding environment, confirm that its treatment or use class is suitable before installation.
Natural Appearance and Variations
Timber is a natural material, so each length will have an individual appearance. Differences in colour, grain pattern and surface texture are normal. Boards may contain knots, resin pockets, minor splits, wane, treatment marks and other naturally occurring characteristics.
Freshly treated timber may have a green or light brown tint, depending on the timber species and preservative used. This colour will normally soften and change as the wood is exposed to daylight and weather.
Changes in moisture content can cause timber to expand, contract, twist or develop small surface checks. These are normal characteristics of wood and do not necessarily affect its suitability for the intended application.
Please note that colours, sizes and finishes can vary slightly due to the manufacturing and pressure-treatment processes. Product photographs should therefore be regarded as representative because the supplied timber may not look exactly the same as the piece shown.
Cutting and Installation
This 4.8m timber can be cut using suitable woodworking equipment. Measure carefully before cutting and ensure that the board is properly supported to improve accuracy and prevent uncontrolled movement.
Cutting, drilling or notching may expose untreated or less-protected areas inside the timber. Apply a compatible cut-end or end-grain timber preservative to these areas in accordance with the manufacturer’s instructions.
Use suitable exterior-grade fixings that are compatible with pressure-treated timber. Galvanised or stainless-steel screws, nails and bolts are commonly chosen for outdoor applications because unsuitable metal fixings can corrode or cause staining.
Wear appropriate gloves, eye protection and a dust mask while cutting or drilling. Work in a ventilated area, wash your hands after handling the timber and dispose of offcuts responsibly. Tanalised timber should never be burned.
Storage and Maintenance
Before installation, store the timber flat and support it evenly along its full length. Keep it raised clear of the ground and protected from prolonged heavy rain while maintaining sufficient ventilation.
Incorrect or uneven storage can encourage bowing, twisting and unwanted movement, particularly with longer 4.8m sections. Allow the timber to adjust to the intended environment before completing projects that depend on precise alignment.
Once installed, the timber can be left to weather naturally or finished with a compatible exterior wood paint, stain or oil. Freshly treated or damp timber should be allowed to dry sufficiently before a decorative finish is applied.
Inspect outdoor timber structures periodically for loose fixings, trapped moisture, exposed cut surfaces and deterioration of any applied coating. Timely maintenance can help preserve both the timber and the finished project.
Tanalised Treated Timber 75 x 150mm 4.8m provides a robust 6×3 section for a wide range of substantial outdoor building and landscaping applications. Its pressure-treated finish offers improved durability compared with untreated wood, while the extended 4.8m length provides useful coverage for larger installations.
Always inspect the actual dimensions, condition, treatment specification and strength grade before installation. Obtain advice from a suitably qualified professional for structural, retaining or load-bearing applications to ensure that the timber and proposed design are appropriate.
