7th Dec 2022 -

6x2 timber is a strong, dependable wood, used within a variety of load-bearing constructions. It can be sold in several finishes, such as pressure treated and PSE. In this guide from Building Materials Nationwide we’ll be looking through the exact UK sizing of 6x2 timber, how it’s sold, and the main uses for it within a building project.

How is 6x2 Timber Sold in the UK?

UK law dictates that products must be sold in metric units, meaning that traditional imperial measurements will not be used within UK websites or builders merchants. While informally these sizes continue to be the dominant terms used when buying timber, you’ll be looking to buy a 150mm x 50mm sized timber beam. This is actually a slightly different size than 6x2 inches (which should technically be about 152.4mm x 50.8mm) but is the equivalent sizing within this country. Sometimes 150 x 47mm timber is also sold in the UK, which is also sold as an equivalent to 6x2 timber. Whenever looking to buy timber, it’s important to bear in mind that the finished size will be smaller than the one stated.

What is the Actual Size of 6x2 Timber?

The listed size of a piece of timber, such as 6x2, is the size that it will be rough sawn to when initially felled. This is a product known as green timber, due to its high water content. In most construction tasks, the moisture level of green timber beams will make them unsuitable, as they will shrink over time. While there are a couple of specific uses for green timber, in most cases it will be dried, and sometimes it will be planed, both of which will reduce the size of a piece of timber.

Kiln-drying involves using a vacuum chamber to reduce the level of moisture in timber to below 20%, allowing it to be used within construction. Planing involves smoothing one or more surfaces of a piece of timber. This will give it an attractive, safe finish and allow it to be used for outward-facing purposes like panelling and furniture. Both of these practices will reduce the size of a piece of timber, meaning that the actual size in mm of a 6x2 timber beam will likely be about 140mm x 38mm.

What Lengths of 6x2 Timber Are Sold in the UK?

6x2 timber will be sold in a variety of lengths within the UK, typically increasing in increments of 30cm or 60cm. For example, our C24 graded 6x2 timber comes in the lengths 2.4m, 3m, 3.6m, 4.2m, and 4.8m.

What Types of 6x2 Timber Are Sold in the UK?

When looking to buy 6x2 timber within the UK, there will be a choice of finishes available, each bringing its own benefits with them. Depending on your needs in timber, you may need to buy wood that is finished in a certain way, or that has been planed or strength graded.

Pressure Treated 6x2 Timber

Pressure-treated 6x2 timber, sometimes called tanalised timber, has been treated with preservatives to increase both moisture and insect resistance. When installed externally or in locations with any levels of moisture, untreated softwood timber is prone to rot and decay. Insects burrowing into timber beams is also a threat, which can cause aesthetic and structural damage. For external use, opting for pressure-treated timber is essential.

Structural C16 or C24 6x2 Timber

When looking to use timber for load-bearing aspects of construction, such as framing, it’s important to choose timber that has been strength graded. Ungraded timber will come with no guarantees about strength, meaning that it can jeopardise structures when used within them. C16 and C24 are strength grades for a softwood timber beam, with the C24 grade representing a greater strength. Timber lengths will be machine tested to ensure that they meet these standards, and are therefore safe to use within construction. How far a 6x2 timber beam can span will depend on its strength grading and the wood it is cut from.

PSE 6x2 Timber

Rough sawn timber will have an uneven look and a coarse surface, looking unappealing within a project and risking splinters to those who come into contact with it. When looking to use wood within a visible surface, or as a feature that will be touched or handled, you should look to buy wood that has been planed. Planing is essentially belt sanding to give a smooth, attractive finish. While timber that has been planed on one or two sides is sometimes available, PSE 6x2 timber, or PSE, will have been planed on every side, leaving sharp corners between them.

CLS 6x2 Timber

CLS timber, short for Canadian lumber standard, is a specific strength and cut of timber that is used for a variety of purposes within construction. CLS 6x2 timber, which is very rarely from Canada when sold within the UK, will meet certain set strength requirements and will be planed on each surface, with curved corners instead of sharp ones.

What is 6x2 Timber Used For?

Within a building project, there are a variety of uses for 6x2 timber, with its size and strength suiting it for strong load-bearing capabilities.

Ridge Beams or Ridge Boards

Ridge beams and ridge boards are different methods of securing roof rafters in place. A ridge beam is at the top of roof construction, with all rafters connected to its longer facing, and with structural support posts at either side. Ridge beams will be load-bearing, requiring a strong timber such as a C16 or C24 6x2 beam. Ridge boards are similarly installed except without the structural supports on either end, and with ceiling joists below the rafters. While this option will not be load bearing, it may still be worth opting for a stronger timber to prioritise a long lifespan, as a ridge board will not be easy to replace.


Alongside the ridge beam or board, you can also use 6x2 timber for the rafters themselves. As rafters are designed to transfer the weight of the roof into load-bearing walls, the rafters themselves will need to be at an appropriate level of strength. Using 6x2 timber graded to C16 or C24 is therefore necessary. When using 6x2 rafters, you should look to use a larger ridge beam, such as an 8x2. In cases where rafters are visible, you’ll want to opt for a PSE timber while in those where the roof isn’t seen rough sawn will be acceptable.

Joists For Deck Framing

The joists within a deck structure will need to both support the weight of foot traffic and resist rainfall. 2x6 timber joists are a great choice, with treated timber options offering everything needed for exterior strength dependent use. Tanalised timber will also resist infestations of wood-boring insects.

House Framing

6x2 timber can be used to frame a timber house, strong enough for the construction of a smaller family home. When looking to frame a house strength is obviously essential, so again C16 or C24 timber should be used, allowing the load-bearing supports to ensure lasting performance. As a house’s frame is usually not visible, rough sawn timber should be acceptable, as long as it has been kiln-dried.

Our Range of Quality 6x2 Timber

Building Materials Nationwide stocks a wide range of timber within our website, which can be delivered across the UK for both professional and personal usage. We work with those in the building industry to save them time and money, offering a comprehensive selection of building products, all sold at competitive pricing. We stock 6x2 timber in several finishes, with pressure treated timberstructural timber, and PSE timber all available. We also offer trade accounts for customers in the industry, gaining them access to a dedicated account manager, our full product range, and our express delivery services. Sign up for a trade account through our website today.