Tanalised Treated Timber 47 x 100mm 3.6m – 4×2 Timber
Tanalised Treated Timber 47 x 100mm 3.6m is a versatile pressure-treated softwood section suitable for outdoor construction, landscaping and general building projects. It is commonly referred to as 4×2 timber, based on its traditional approximate imperial dimensions of 4 inches by 2 inches.
The 47 x 100mm section is one of the most commonly used timber sizes for building, garden and DIY work. Its practical 3.6-metre length provides additional coverage compared with a standard 3.0m length while remaining relatively straightforward to transport, store and handle.
The timber has undergone a controlled pressure-treatment process to provide additional protection against fungal decay and wood-destroying insects. This treatment improves its durability compared with untreated softwood when it is correctly specified, installed and maintained in an appropriate environment.
Product dimensions
The nominal product dimensions are:
- Metric section: 47mm x 100mm
- Common imperial name: 4×2 timber
- Length: 3.6m
- Material: Treated softwood
- Treatment: Pressure treated or tanalised
- Suitable for: Building, landscaping and outdoor projects
The name 4×2 is a traditional trade description rather than an exact imperial conversion. The stated metric dimensions should be used when measuring, planning and cutting the timber.
What is tanalised timber?
Tanalised timber is softwood that has been treated with wood preservative using a controlled vacuum and pressure process. This encourages the preservative to penetrate more deeply into the timber than a simple surface-applied coating.
The treatment helps protect the wood against fungal decay and attacks from wood-destroying insects. This makes it a practical material for many outdoor, exposed and moisture-prone projects.
Pressure treatment does not make timber completely waterproof or prevent natural weathering. The wood can still absorb and release moisture, which may result in movement, shrinkage, surface checking and colour changes.
Cutting, drilling or notching the timber may expose internal wood that has not received the same level of preservative protection. Coat these areas with a compatible end-grain wood preservative during installation.
Common uses for 4×2 treated timber
The 47 x 100mm section is highly adaptable and can be used for many outdoor and general construction applications.
Depending on its strength grade and the project specification, possible uses include:
- Outdoor timber frameworks
- Garden buildings and sheds
- Landscaping projects
- Timber supports and bearers
- Garden screens and dividers
- Agricultural and equestrian structures
- Raised garden features
- External carpentry and joinery
- General repair and maintenance work
- Bespoke garden projects
- Load-bearing members where correctly graded
- Outdoor DIY construction
Where structural performance is required, confirm that the timber has the correct strength classification for the proposed application. Tanalised timber should not automatically be assumed to be C16 or C24 unless the product is specifically marked and sold with that grade.
The required span, loading, support spacing, connections and fixings should be confirmed by a suitably competent person for load-bearing projects.
Benefits of the 3.6m length
The 3.6-metre length is a convenient option for many medium-sized building and landscaping jobs. It provides greater reach than a 3.0m length without the additional handling requirements associated with 4.8m or 6.0m timber.
The product can be installed as a full length or cut into multiple smaller components. Planning the required cuts before beginning work can help reduce waste and make efficient use of the available material.
Timber weight will vary depending on its moisture content. Suitable lifting and handling procedures should be followed, especially when carrying several lengths together.
Natural characteristics of timber
Timber is a natural material, meaning every length will vary in grain pattern, colour, knots and surface texture. These differences are expected and form part of the product’s natural appearance.
Knots, resin pockets, minor splits and surface checking may be present. These features are not automatically product defects, although their suitability will depend on the intended application and any relevant grading requirements.
Pressure treatment introduces moisture into the timber. As it dries, some shrinkage, twisting, bowing or cupping may occur. Appropriate storage, acclimatisation and installation can help manage this natural movement.
Newly treated timber may have a green or brown appearance depending on the preservative system used. The colour will generally soften and weather gradually following outdoor exposure.
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 4×2 is an approximate imperial description rather than a guarantee of exact finished measurements. If precise dimensions are important, measure the timber before installation or contact us to confirm the specification of the available stock.
Allow the timber to acclimatise where appropriate before completing work that requires close-fitting joints or accurate dimensions.
Cutting and installation
Use suitable woodworking tools fitted with sharp blades when cutting or drilling the timber. Wear protective gloves, eye protection and appropriate respiratory protection when handling, sawing or sanding treated wood.
Carry out cutting in a well-ventilated area 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 suitable intervals. Protect it from prolonged saturation while allowing air to circulate around each length.
For visible outdoor projects, a compatible wood oil, stain or protective coating may be applied once the timber has dried sufficiently. Follow the coating manufacturer’s instructions for preparation and moisture content.
Inspect external timber periodically, paying particular attention to cut ends, joints, fixing points and areas where water may collect.
Key benefits
- Versatile 47 x 100mm timber section
- Commonly known as 4×2 timber
- Practical 3.6m length
- Pressure treated against decay and insects
- Suitable for outdoor frameworks and landscaping
- Useful for garden and agricultural structures
- Can be cut for different project requirements
- Relatively easy to transport and handle
- More durable than untreated softwood
- Suitable for professional and DIY construction
Tanalised Treated Timber 47 x 100mm 3.6m – 4×2 Timber is a versatile choice for garden structures, outdoor 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.
