Tanalised Treated Timber 47 x 175mm 4.8m – 7×2 Timber
Tanalised Treated Timber 47 x 175mm 4.8m is a versatile pressure-treated softwood section suitable for building, landscaping and outdoor construction projects. It is commonly referred to as 7×2 timber, based on its traditional approximate imperial dimensions of 7 inches by 2 inches.
The combination of a 175mm depth and a practical 4.8-metre length makes this timber useful for frameworks and other substantial outdoor projects. It offers a deeper profile than common 4×2 or 6×2 timber, making it suitable for applications requiring a larger timber section, subject to the correct design and specification.
The timber has been pressure treated with wood preservative to provide additional protection against fungal decay and wood-destroying insects. This treatment helps extend its service life when it is correctly installed and maintained in an appropriate environment.
Product dimensions
The nominal product dimensions are:
- Metric section: 47mm x 175mm
- Common imperial name: 7×2 timber
- Length: 4.8m
- Material: Treated softwood
- Treatment: Pressure treated or tanalised
- Suitable for: Building, landscaping and outdoor projects
The traditional name 7×2 is a common trade description rather than an exact conversion of the metric dimensions. The stated 47 x 175mm size should be used when planning and measuring the project.
What is tanalised timber?
Tanalised timber is softwood that has been treated with preservative using a controlled vacuum and pressure process. This encourages the preservative to penetrate deeper into the timber than a basic surface-applied coating.
The treatment helps protect the wood against fungal decay and attacks from wood-destroying insects. It makes the timber more suitable than untreated softwood for many outdoor, exposed and moisture-prone applications.
Pressure treatment does not make the wood completely waterproof or maintenance-free. Exposure to moisture, sunlight and changing temperatures can still cause natural movement, surface checking and gradual colour changes.
Cut ends, notches and drilled holes can expose internal areas that have not received the same level of protection. Apply a suitable end-grain wood preservative to these areas during installation.
Common uses for 7×2 treated timber
This 47 x 175mm timber can be used for numerous outdoor and general construction projects where its dimensions and specification are appropriate.
Possible applications include:
- Outdoor timber frameworks
- Garden structures and buildings
- Landscaping projects
- Timber supports and bearers
- Agricultural and equestrian applications
- Raised garden structures
- External carpentry
- General construction work
- Bespoke garden features
- Repairs to existing timber structures
- Load-bearing members where correctly graded
- Larger outdoor DIY projects
Where the timber is intended to carry structural loads, confirm that it has the correct strength grade for the proposed application. Tanalised timber should not automatically be assumed to be C16 or C24 unless this is clearly marked and stated in the product specification.
The required span, loading, support spacing and fixing method should be confirmed by a suitably competent person where structural performance is required.
Benefits of pressure-treated timber
Untreated softwood can be vulnerable to decay when it is exposed to moisture or used outdoors. Pressure treatment introduces preservative into the timber to improve its resistance to common biological causes of deterioration.
This provides several practical benefits:
- Increased durability compared with untreated softwood
- Protection against fungal decay
- Protection against wood-destroying insects
- Suitable for many outdoor applications
- Reduced need for immediate preservative treatment
- Useful for landscaping and garden structures
- Can be cut and worked using suitable tools
- Suitable for professional and DIY projects
The correct treatment or use class must still be selected for the intended environment, particularly where timber will be in direct ground contact or exposed to persistent moisture.
Natural characteristics of timber
Timber is a natural product, so no two lengths will be visually identical. Variations in grain, colour, knots and surface texture are normal and contribute to the character of the material.
Knots, resin pockets, minor splits and surface checking may be present and are not automatically product defects. The acceptability of these characteristics will depend on the intended application and any applicable grading requirements.
Pressure treatment adds moisture to the timber. As it dries, some shrinkage, twisting, bowing or cupping may occur. Correct storage and installation can help manage this natural movement.
The timber may initially have a green or brown appearance depending on the preservative treatment used. This colour will normally fade and weather gradually after outdoor installation.
Important sizing information
Please note: Timber dimensions are nominal and may vary slightly due to the manufacturing process, pressure treatment, moisture content and natural movement of the wood.
The name 7×2 refers to the timber’s common approximate imperial size. Customers requiring highly accurate dimensions should measure each length before installation or contact us to confirm the specification of the available stock.
Allow the timber to acclimatise appropriately before completing work involving precise joints or close tolerances.
Cutting and installation
Use suitable woodworking tools with sharp blades when cutting or drilling the timber. Wear gloves, eye protection and suitable respiratory protection when handling, sawing or sanding treated wood.
Work in a well-ventilated area and avoid breathing timber dust. Dispose of sawdust and offcuts responsibly. Pressure-treated timber should not be burned on a garden bonfire, domestic fire or in a wood-burning appliance.
Treat all freshly cut ends, drilled holes and notches with a compatible end-grain preservative. Use corrosion-resistant fixings suitable for treated timber, especially in outdoor or damp environments.
Where this timber is used structurally, supports, connections and fixings should 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 air to circulate around the lengths.
A compatible wood stain, oil or protective coating may be applied to visible outdoor timber once it has dried sufficiently. Always follow the coating manufacturer’s preparation and moisture-content requirements.
Inspect external timber periodically, paying particular attention to cut ends, joints, fixing points and areas where water may collect.
Key benefits
- Practical 47 x 175mm timber section
- Commonly known as 7×2 timber
- Pressure treated against decay and insects
- Suitable for outdoor and landscaping projects
- Useful for frameworks, supports and garden structures
- Can be cut to meet project requirements
- Suitable for professional and DIY construction
- More durable than untreated softwood
- Versatile for general building applications
Tanalised Treated Timber 47 x 175mm 4.8m – 7×2 Timber offers a versatile and substantial softwood section for outdoor construction, landscaping and general building projects. Always verify the exact dimensions, treatment level and strength grade against the requirements of the intended application before installation.
