Tanalised Treated Timber 47 x 175mm 3.0m – 7×2 Timber
Tanalised Treated Timber 47 x 175mm 3.0m is a substantial pressure-treated softwood section suitable for outdoor construction, landscaping and general building projects. It is commonly referred to as 7×2 timber, based on its traditional approximate imperial dimensions of 7 inches by 2 inches.
The 175mm depth provides a more substantial profile than common 4×2, 5×2 or 6×2 timber. Its convenient 3.0-metre length is relatively straightforward to transport, store and manoeuvre while providing enough material for a broad range of garden and building applications.
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 the timber is correctly specified, installed and maintained in suitable external conditions.
Product dimensions
The nominal product dimensions are:
- Metric section: 47mm x 175mm
- Common imperial name: 7×2 timber
- Length: 3.0m
- Material: Treated softwood
- Treatment: Pressure treated or tanalised
- Suitable for: Building, landscaping and outdoor projects
The name 7×2 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 that has been treated with wood preservative using a controlled vacuum and pressure process. This encourages the treatment to penetrate further into the material than a standard brush-applied surface coating.
The preservative helps protect the wood against fungal decay and attacks from wood-destroying insects. It can help extend the timber’s service life when the product is used in a suitable outdoor or exposed environment.
Pressure treatment does not make timber entirely waterproof or maintenance-free. The wood can still absorb and release moisture, resulting in natural movement, shrinkage, surface checking, weathering and gradual changes in colour.
Cutting, drilling or notching may expose internal areas that have not received the same level of preservative treatment. Apply a compatible end-grain wood preservative to all newly exposed surfaces during installation.
Common uses for 7×2 treated timber
The 47 x 175mm section is suitable for numerous substantial outdoor and general construction projects.
Depending on its strength grade and the project specification, possible applications include:
- Outdoor timber frameworks
- Garden buildings and structures
- Landscaping projects
- Timber supports and bearers
- Agricultural and equestrian construction
- Raised garden features
- External carpentry and joinery
- General building work
- Bespoke outdoor structures
- Repairs to existing timber frameworks
- Load-bearing members where correctly graded
- Garden and DIY construction
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, loading, support spacing, connections and fixing arrangement should be established by a suitably competent person for structural projects.
Benefits of the 3.0m length
The 3.0-metre length is practical for many everyday construction and landscaping jobs. It is easier to transport, store and move around a typical site than longer 3.6m, 4.8m or 6.0m timber.
The product can be installed as a full length or divided into several smaller components. Preparing a cutting schedule before work begins can help reduce offcuts and make efficient use of each piece.
Although the length is relatively manageable, the deep 175mm section and moisture retained from treatment can add weight. Appropriate lifting and handling procedures should therefore be followed.
Benefits of pressure-treated softwood
Pressure treatment provides several advantages for timber intended for appropriate outdoor use:
- Additional protection against fungal decay
- Protection against wood-destroying insects
- Improved durability compared with untreated timber
- Suitable for many external projects
- Useful for garden and landscaping construction
- Can be cut and worked using suitable tools
- Practical for repairs and maintenance
- Suitable for trade and DIY applications
The correct treatment or use class must still be chosen for the intended environment. Timber in direct contact with the ground or exposed to persistent moisture may require a particular treatment specification.
Natural characteristics of timber
Timber is a natural product, so individual lengths will vary in grain pattern, shade, knots and surface texture. These differences are normal and contribute to the natural appearance of the wood.
Knots, resin pockets, minor splits and surface checking may be present. These features do not automatically indicate a defect, 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 natural shrinkage, twisting, bowing or cupping may occur. Correct storage, acclimatisation and installation can help manage this movement.
Newly treated timber may initially have a green or brown appearance depending on the preservative system used. Its colour will generally fade 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 7×2 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 involves accurate measurements or close-fitting joints.
Cutting and installation
Use suitable woodworking equipment 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 location 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 pressure-treated timber, particularly in external or regularly damp environments.
Where the timber forms part of a load-bearing structure, all supports, connections and fixings should follow the approved design and be suitable 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 providing sufficient airflow around each length.
For visible outdoor projects, a compatible wood stain, oil or protective coating may be applied after the timber has dried sufficiently. Follow the coating manufacturer’s preparation and moisture-content instructions.
Inspect external timber periodically, paying particular attention to joints, cut ends, fixing points and areas where water might collect.
Key benefits
- Substantial 47 x 175mm timber section
- Commonly known as 7×2 timber
- Convenient 3.0m length
- Pressure treated against decay and insects
- Suitable for outdoor frameworks and landscaping
- Useful for garden and agricultural structures
- Easier to handle than longer timber lengths
- Can be cut for different project requirements
- More durable than untreated softwood
- Suitable for professional and DIY construction
Tanalised Treated Timber 47 x 175mm 3.0m – 7×2 Timber offers a substantial section in a manageable length for 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.
