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4x2 Timber
Shop our 4x2 timber range for stud walls, framing, roofing, joinery and general building work. Compare the available lengths, finished dimensions and specifications to find the right timber for the job. Order online for delivery or Click & Collect from your nearest MGN Builders Merchants branch.
47mm x 100mm C24 Treated Carcassing Timber (4" x 2")-£0.86From £4.75 £3.96 As low as From £5.62 £4.68 Regular Price
47mm x 100mm to 0mm Treated Timber Firring (4" x 2")From £12.10 £10.08 As low as
4x2 Timber: A Versatile Size for Building Projects
In UK timber terminology, 4x2 timber is the nominal name for a section measuring approximately four inches by two inches before drying and machining. Its nominal metric equivalent is 100mm x 50mm. If you are comparing 4x2 timber in cm, this is approximately 10cm x 5cm.
This does not mean that every piece will finish at exactly 100mm x 50mm. Across the MGN range, you may see finished sections such as 47mm x 100mm, 44mm x 94mm or 38mm x 89mm. Drying, planing and regularising can reduce the original dimensions while producing a more consistent section.
These differences in 4x2 timber dimensions are normal and do not mean that the product has been incorrectly sized. If you are checking 4x2 timber in mm, use 100mm x 50mm as the nominal reference and the finished dimensions on the product page for accurate setting out, cutting and fitting.
Common Applications for 4x2 Timber
4x2 is a familiar working size on building and renovation projects. Its intended use depends on the specification and finish of the individual product.
- Stud walls and partitions: 4x2 stud timber is used for studs, head and sole plates, and noggins.
- Timber framing: 4x2 framing timber can form wall frames and supporting frameworks where specified.
- Joists and rafters: The section may be used for floor or roof members in appropriate designs.
- Roofing work: Typical uses include framing, trimming and firrings used to form falls.
- Joinery: Smoother sections can be used for visible frames, workbench components and fitted pieces.
- General building: Useful for blocking, grounds, bracing and repair work.
Structural applications must follow the required grade, section, span and spacing specified in the project design. For alternative construction sections and lengths, explore our wider carcassing timber range.
4x2 Timber Specifications to Check
Two pieces described as 4x2 may have different finishes, grades and intended uses. The name tells you the nominal size, but not how the timber will perform.
- Strength grade: For 4x2 structural timber, match the declared grade to the project specification. Do not assume ungraded timber is suitable for load-bearing work. Where a project specifically calls for C24, check the available lengths and specification of our 47mm x 100mm C24 treated carcassing timber (4" x 2").
- Treatment and Use Class: Select 4x2 treated timber according to its declared Use Class and expected exposure, rather than relying on colour alone. Preservative treatment improves durability but does not make timber waterproof.
- Surface finish: Planed stock provides a smoother surface, while sawn or regularised sections are often used where appearance is less important.
- Actual section size: Use the finished width and thickness when matching insulation, sheet materials, connectors or existing timberwork.
- Intended environment: Confirm whether the product is intended for dry interiors, damp locations, sheltered exterior work or direct exposure.
- Compatible fixings: Fixing dimensions must suit the finished section. When fixing treated 4x2 timber, use corrosion protection compatible with the preservative and installation environment.
The nominal 4x2 size does not determine load capacity or safe span. Performance depends on the finished section, strength grade, span, spacing, loads and support conditions. These requirements must come from the project design rather than the 4x2 name alone.
Planning and Working with 4x2 Timber
Available 4x2 timber lengths vary between products, so check the selectable options before preparing your order. Starting with a clear cutting list will help you calculate quantities and make better use of each length.
- Prepare a cutting list: Record the quantity and finished length of every component.
- Combine repeated cuts: Group matching components across suitable stock lengths.
- Allow for waste: Include saw cuts, end trimming, defects and site adjustments.
- Consider site access: Longer sections may reduce joints but can be harder to transport, store and handle.
- Inspect before cutting: Look for excessive bowing, twisting, splits or other damage.
- Store timber flat: Keep it off the ground on level, evenly spaced supports with adequate ventilation.
- Protect freshly cut ends: Re-treat exposed end grain with a compatible preservative, following the manufacturer’s instructions.
For larger orders, an MGN branch team can help confirm current stock, available lengths and suitable collection or delivery options before you travel.
Order 4x2 Timber from MGN Builders Merchants
Compare current 4x2 timber prices, finished dimensions and available lengths in the product listings above. If the project calls for a deeper nominal section, you can also compare our 5x2 timber range. The 4x2 selection covers timber for structural work, studwork, roofing details, general construction and joinery.
You can buy 4x2 timber online for delivery across London, Essex, Kent and the South East. Enter your postcode to check delivery availability, lead times and the minimum order value for your area.
Alternatively, select Click & Collect at checkout and collect your order from:
FAQs
What is 4x2 timber in mm?
In UK merchant terminology, 4x2 timber - also searched for as timber 4x2 - is the nominal name for a section approximately four inches by two inches. This corresponds to a nominal metric size of 100mm x 50mm, or 10cm x 5cm. Finished dimensions are usually smaller after drying and machining, so always check the actual section stated on the product page.
What lengths does 4x2 timber come in?
Lengths available across the MGN range include 2.4m, 3m, 3.6m, 4.2m, 4.8m and 6m. Availability varies by grade, treatment and finish, so check the selectable options on the relevant product page or contact your local MGN branch before ordering.
Can 4x2 treated timber be used outdoors?
Yes, provided that the treatment and declared Use Class are suitable for the intended exposure. Pressure-treated or tanalised timber intended for exterior above-ground use may not be suitable for direct ground contact. Treatment does not make wood waterproof, so appropriate detailing and drainage remain important. Freshly cut ends should be re-treated where required by the product instructions.
Can 4x2 timber be used for a stud wall?
Yes. 4x2 stud timber is commonly used for studs, head and sole plates, and noggins. CLS timber is often selected for this work because its regular dimensions and eased edges make it easier to handle. For structural or load-bearing walls, the finished section, strength grade, stud spacing and fixings must follow the project design.
Can 4x2 timber be used for joists or rafters?
It can be used where a 4x2 section is supported by the project specification, structural calculations or an appropriate span table. Safe spans cannot be determined from the nominal size alone. They also depend on the finished dimensions, strength grade, spacing, imposed loads and support conditions.
Should I use planed or sawn 4x2 timber?
Planed timber, often described as PAR or PSE, has a smoother surface and is generally more suitable for visible joinery or work requiring a cleaner finish. Sawn or regularised carcassing timber is usually preferred for framing and concealed building work. Compare the actual finished dimensions as well as the surface finish before selecting a product.
How much does 4x2 timber cost?
The cost depends on the length, actual section, strength grade, treatment and surface finish. When comparing timber 4x2 prices, also check whether the price is shown per length or per metre and whether VAT and delivery are included. Current prices are displayed with the products above, while larger or mixed orders can be quoted through an MGN branch.