Tanalised Treated Timber 47 x 125mm 4.8m – 5×2 Timber
Tanalised Treated Timber 47 x 125mm 4.8m is a versatile pressure-treated softwood section suitable for outdoor construction, landscaping and general building projects. It is commonly referred to as 5×2 timber, based on its traditional approximate imperial dimensions of 5 inches by 2 inches.
The 125mm depth creates a useful intermediate section between commonly used 4×2 and 6×2 timber. This makes it suitable for projects requiring a more substantial section than 4×2 without the additional depth and weight associated with larger timber sizes.
Its practical 4.8-metre length provides flexibility for larger frameworks and outdoor structures. Where suitable for the design, the longer format may help reduce the number of joints required. It can also be cut into several shorter components to meet the needs of the project.
The timber has undergone a controlled pressure-treatment process to provide additional protection against fungal decay and wood-destroying insects. This makes it more durable than untreated softwood when correctly specified, installed and maintained in an appropriate environment.
Product dimensions
The nominal product dimensions are:
- Metric section: 47mm x 125mm
- Common imperial name: 5×2 timber
- Length: 4.8m
- Material: Treated softwood
- Treatment: Pressure treated or tanalised
- Suitable for: Building, landscaping and outdoor projects
The term 5×2 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 treatment to penetrate deeper into the timber than a standard brush-applied surface coating.
The preservative helps protect the wood against fungal decay and attacks from wood-destroying insects. It can extend the product’s service life when the timber is correctly selected, installed and maintained in suitable outdoor conditions.
Pressure treatment does not make timber entirely waterproof or prevent all natural weathering. The wood can still absorb and release moisture, leading to movement, shrinkage, surface checking and gradual changes in colour.
Cutting, drilling or notching the timber exposes internal wood that may not have received the same level of treatment. Apply a compatible end-grain preservative to all newly exposed areas during installation.
Common uses for 5×2 treated timber
The 47 x 125mm section is suitable for a broad variety of outdoor and general construction projects. Its suitability for a particular application will depend on its strength grade, treatment level and the approved design.
Possible applications include:
- Outdoor timber frameworks
- Garden sheds and buildings
- Landscaping projects
- Timber supports and bearers
- Garden screens and dividers
- Agricultural and equestrian structures
- Raised garden features
- External carpentry and joinery
- General building work
- Bespoke outdoor structures
- Repairs to existing timber frameworks
- Load-bearing members where correctly graded
Where the timber will carry structural loads, confirm that it has the correct strength classification. 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, load, support spacing, connections and fixings should be established by a suitably competent person for structural installations.
Benefits of the 4.8m length
The 4.8-metre length offers useful flexibility for medium-to-large building and landscaping projects. Where appropriate for the design, it can provide longer continuous runs and reduce the need for joints.
It may also be cut into multiple smaller components. Preparing a cutting plan before beginning work can help minimise waste and make efficient use of the available material.
Consider access and handling arrangements before ordering. Ensure there is sufficient space to unload, store, turn and position a 4.8m length safely.
The weight of the timber will vary depending on its moisture content. Appropriate lifting assistance and safe manual-handling procedures should be used when moving multiple lengths.
Benefits of pressure-treated softwood
Using pressure-treated timber provides several practical advantages for outdoor projects:
- Additional protection against fungal decay
- Protection against wood-destroying insects
- Improved durability compared with untreated softwood
- Suitable for many external applications
- Useful for garden and landscaping projects
- Can be cut and worked with suitable tools
- Suitable for professional and DIY construction
- Supplied ready for appropriate external use
The correct treatment or use class must still be selected for the intended environment. Timber installed in direct ground contact or exposed to persistent moisture may require a specific treatment classification.
Natural characteristics of timber
Timber is a natural material, so every length will differ in grain, shade, knots and surface texture. These variations are expected and form part of the material’s natural appearance.
Knots, resin pockets, minor splits and surface checking may be present. These characteristics do not automatically indicate a defect, although their suitability will depend on the application and any applicable grading requirements.
The pressure-treatment process introduces moisture into the wood. As the timber dries, some natural shrinkage, twisting, bowing or cupping may occur. Suitable storage and installation can help manage this movement.
Newly treated timber may initially have a green or brown appearance depending on the treatment system used. Its colour will generally fade and weather gradually following exposure to outdoor conditions.
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 5×2 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.
Allowing the timber to acclimatise appropriately can be beneficial where the project requires precise joints or close-fitting components.
Cutting and installation
Use suitable woodworking tools fitted with sharp blades when cutting or drilling this timber. Wear protective gloves, eye protection and appropriate respiratory protection while handling, sawing or sanding treated wood.
Complete cutting work in a well-ventilated area and avoid breathing timber dust. Sawdust and offcuts should be collected and disposed of responsibly. Pressure-treated timber 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 moisture-prone environments.
Where the timber forms part of a load-bearing structure, all supports, connections and fixings must follow the approved design and be suitable for the anticipated loads.
Storage and maintenance
Store the timber flat, raised off the ground and supported at suitable intervals. Protect it from prolonged saturation while allowing sufficient airflow around each length.
A compatible wood stain, oil or protective coating may be applied to visible external timber once it has dried sufficiently. Follow the coating manufacturer’s preparation and moisture-content instructions.
Inspect outdoor timber periodically, paying particular attention to cut ends, joints, fixing points and horizontal areas where water may collect.
Key benefits
- Versatile 47 x 125mm timber section
- Commonly known as 5×2 timber
- Supplied in a useful 4.8m length
- May reduce joints in larger frameworks
- Pressure treated against decay and insects
- Suitable for outdoor construction and landscaping
- Useful for garden and agricultural structures
- Can be cut to meet different requirements
- More durable than untreated softwood
- Suitable for professional and DIY projects
Tanalised Treated Timber 47 x 125mm 4.8m – 5×2 Timber combines a practical intermediate section with a useful length for outdoor construction, landscaping and general building projects. Always confirm its dimensions, treatment level and strength grade against the requirements of the intended application before installation.
