Tanalised Treated Timber 47 x 75mm 4.2m – 3×2 Timber
Tanalised Treated Timber 47 x 75mm 4.2m is a practical pressure-treated softwood section suitable for outdoor construction, landscaping and general building projects. It is commonly referred to as 3×2 timber, based on its traditional approximate imperial dimensions of 3 inches by 2 inches.
The compact 47 x 75mm section is easy to work with and can be used for many light-to-medium-duty frameworks, garden structures and general repair tasks. Its useful 4.2-metre length offers additional coverage and may help reduce the number of joints required when compared with shorter timber lengths.
The timber has undergone a controlled pressure-treatment process to provide additional protection against fungal decay and wood-destroying insects. This improves its durability compared with untreated softwood when correctly specified, installed and maintained in suitable external conditions.
Product dimensions
The nominal product dimensions are:
- Metric section: 47mm x 75mm
- Common imperial name: 3×2 timber
- Length: 4.2m
- Material: Treated softwood
- Treatment: Pressure treated or tanalised
- Suitable for: Building, landscaping and outdoor projects
The term 3×2 is a traditional trade description rather than an exact imperial conversion. Use the stated metric dimensions when planning, measuring and cutting the timber.
What is tanalised treated timber?
Tanalised timber is softwood treated with wood preservative using a controlled vacuum and pressure process. This encourages the preservative to penetrate further into the wood than an ordinary brush-applied surface treatment.
The treatment helps protect the timber against fungal decay and attacks by wood-destroying insects. It can help extend the timber’s service life when used in suitable outdoor, exposed and moisture-prone applications.
Pressure treatment does not make timber completely waterproof or prevent all natural weathering. The wood can still absorb and release moisture, resulting in movement, shrinkage, surface checking and gradual changes in colour.
Cutting, drilling or notching the timber can expose internal wood that may not have received the same level of protection. Apply a compatible end-grain wood preservative to all freshly exposed surfaces during installation.
Common uses for 3×2 treated timber
The 47 x 75mm section is suitable for a wide variety of garden, landscaping and general construction projects.
Depending on its strength grade and the project specification, possible applications include:
- Lightweight outdoor frameworks
- Garden structures and features
- Shed frameworks and repairs
- Landscaping projects
- Timber supports and noggins
- Garden screens and dividers
- Agricultural and equestrian projects
- Raised garden features
- External carpentry and joinery
- General repair and maintenance work
- Bespoke outdoor structures
- Load-bearing applications where correctly graded
Where structural performance is required, confirm that the timber has the correct strength classification. Tanalised timber should not automatically be assumed to be C16 or C24 unless it is specifically marked and sold with that grade.
A suitably competent person should determine the required spans, loads, support spacing, connections and fixing arrangements for structural applications.
Benefits of the 4.2m length
The 4.2-metre length provides greater reach than common 3.0m or 3.6m timber while remaining easier to handle than longer 4.8m or 6.0m pieces.
Where suitable for the design, the longer length can help reduce joints and create a more continuous framework. It can also be divided into several shorter components for use across the project.
Preparing a cutting schedule before starting work may help reduce waste and make efficient use of the complete length.
Ensure there is enough room to unload, store and manoeuvre the timber safely. The weight of each piece will vary depending on its moisture content, so suitable handling methods should be used.
Benefits of pressure-treated softwood
Pressure treatment provides several practical advantages for appropriate outdoor applications:
- Additional protection against fungal decay
- Protection against wood-destroying insects
- Greater durability than untreated softwood
- Suitable for many external projects
- Useful for garden and landscaping work
- Can be cut and worked using suitable tools
- Practical for repairs and maintenance
- Suitable for professional and DIY projects
The correct treatment or use class must still be selected for the intended environment. Timber used in direct ground contact or exposed to persistent moisture may require a different treatment specification.
Natural characteristics of timber
Timber is a natural material, so individual lengths will vary in grain, shade, knots and surface texture. These differences are expected and contribute to the wood’s natural appearance.
Knots, resin pockets, minor splits and surface checking may be visible. These characteristics are not automatically product defects, although their suitability will depend on the intended use and any relevant grading requirements.
Pressure treatment introduces moisture into the timber. As the wood dries, some natural shrinkage, twisting, bowing or cupping may occur. Appropriate storage and installation can help manage this movement.
Newly treated timber may initially appear green or brown depending on the preservative system used. The colour will generally fade and weather gradually after installation outdoors.
Important sizing information
Please note: Timber dimensions are nominal and may vary slightly due to machining, pressure treatment, moisture content and the natural movement of the wood.
The common name 3×2 is an approximate imperial description rather than a guarantee of exact finished dimensions. Customers requiring precise measurements should check the timber before installation or contact us to confirm the current stock specification.
Allow the timber to acclimatise where appropriate before completing work that requires precise joints or close-fitting sections.
Cutting and installation
Use suitable woodworking tools fitted with sharp blades when cutting or drilling the timber. Wear protective gloves, eye protection and suitable respiratory protection when handling, sawing or sanding treated wood.
Carry out cutting work in a well-ventilated location and avoid breathing timber dust. Collect sawdust and offcuts for responsible disposal. Pressure-treated wood must not be burned on domestic fires, in wood-burning appliances or on garden bonfires.
Apply a suitable end-grain preservative to all cut ends, drilled holes and notches. Use corrosion-resistant fixings compatible with treated timber, particularly in external or regularly damp environments.
Where the timber forms part of a load-bearing structure, its supports, connections and fixings must follow the approved design and be appropriate for the anticipated loads.
Storage and maintenance
Store the timber flat, raised above the ground and supported at appropriate intervals. Protect it from prolonged saturation while allowing sufficient ventilation around each length.
For visible outdoor projects, a compatible wood stain, oil or protective coating may be applied once the timber has dried sufficiently. Follow the coating manufacturer’s preparation and moisture-content instructions.
Inspect external timber periodically, paying particular attention to cut ends, joints, fixing points and areas where water might collect.
Key benefits
- Practical 47 x 75mm timber section
- Commonly known as 3×2 timber
- Useful 4.2m length
- Pressure treated against decay and insects
- Suitable for outdoor frameworks and landscaping
- Useful for garden structures and repairs
- May reduce joints in suitable frameworks
- Can be cut for different project requirements
- More durable than untreated softwood
- Suitable for professional and DIY construction
Tanalised Treated Timber 47 x 75mm 4.2m – 3×2 Timber offers a practical section and useful length for garden structures, lightweight frameworks, landscaping and general building projects. Always confirm its exact dimensions, treatment level and strength grade against the requirements of the intended application before installation.
