Every build reaches a point where the timber must be reliable, not just acceptable. Frames need to stay square. Fixings need to hold. The structure should not move once the job is done, because fixing it later costs time, money and effort.
4×2 treated timber is chosen for that stage of a project. It is used when strength matters more than appearance and when the build needs to cope with load, moisture and everyday use. Familiar to trades and DIYers across the UK, this size forms the structural backbone of homes, gardens and site builds where performance comes first.
What is 100x47mm treated timber?
100x47mm treated timber, often called 4×2 treated C16 timber, is a pressure treated structural softwood section used across construction and outdoor projects. It is a familiar size on UK sites because it performs consistently in both internal and external builds.
As 100×47 C16 treated timber, it is graded for strength and consistency, then pressure treated to protect against rot, moisture and insects. This treatment makes it suitable for damp conditions and external use, including gardens and ground-level structures, when installed correctly.
That is why 4×2 green timber is so common in the UK. It handles exposure well, stays stable over time and works outdoors without unnecessary complications.
In British homes and gardens, this size quietly does a lot of structural work. It is used to frame garden rooms and sheds, support raised flower beds and planters, and form the base of seating areas, pergolas and relaxed outdoor spaces. It also sits behind decking and fencing as a hidden support and is widely used for stud walls inside garages and extensions.
What is carcassing treated timber 4×2 used for?
Carcassing timber 4×2 is used wherever structure comes first, and finish comes later. It is the timber that everything else relies on.
Inside the house, it forms stud walls, partitions, floor supports, and internal frames. Outside, it becomes the skeleton of sheds, decking frames, pergolas, and garden builds that must cope with moisture and temperature changes.
Because this is 4×2 treated carcassing timber, it is designed to be fixed, loaded, and trusted. It is chosen when timber needs to stay straight once installed, not constantly adjusted or replaced.
Stud wall construction and internal framing
Shed bases and garden structures
Decking subframes and support rails
Raised beds, seating frames, and outdoor storage
General site work where strength and stability matter
This is why builders keep coming back to 100×47 treated timber. It fits standard fixings. It behaves predictably. It does the job without surprises.
Benefits of 4×2 treated C16 timber
The main benefit of 4×2 treated C16 timber is that it just works. It is strong enough for everyday structural jobs and predictable once it is fixed in place. You put it in, build on it and move on with the job. Because it is treated, the timber copes better with damp conditions. Rain, moisture and typical UK garden use is not a big issue but best kept dry. That makes it suitable for sheds, decking frames, stud walls and outdoor structures where untreated timber would not last. This size is also easy to handle. It cuts cleanly, takes fixings well and fits standard construction details, which saves time on site or at home.
Why choose our 4×2 treated timber?
Most builders buying 4×2 treated timber want three things. A fair price, timber that is ready to use, and delivery that does not slow the job down. That is exactly how this range is set up.
At Sheet Materials Wholesale, our 4×2 treated timber is priced to make sense for both trade and DIY. You get solid value for money, with competitive pricing, whether you are buying a few lengths or placing a bulk order. For larger jobs, volume discounts and pallet quantities are available, and trade discounts apply where relevant. If you need numbers quickly, we offer fast quotes in minutes, not days.
All timber is supplied from UK stock, so there is no waiting for imports or uncertain lead times. Orders are dispatched with fast UK delivery, with next-day delivery available on selected products. Delivery can be made kerbside to the site or home, which keeps things simple, whether you are on a building site or working from your garden.
This timber is project-ready stock. It arrives treated, graded and ready to fix. No extra preparation. No guessing. You also receive a VAT invoice with your order, and full order tracking, so you know exactly when your delivery is due.
4×2 treated timber is supplied in the standard 100mm x 47mm section and graded to C16 for structural use. The timber is available in practical lengths of 2400mm, 3000mm and 3600mm, making it easy to choose the right size for framing, garden builds and general construction work.
If you want reliable 4×2 treated timber, priced properly, delivered fast and backed by clear information, this is exactly what this range is for.
At Sheet Materials Wholesale, you can purchase 4×2 Treated Timber at low wholesale prices with fast nationwide delivery for most of items within 1-3 working days across the UK. Next-day delivery is also available on most orders. Competitive rates guaranteed.
FAQ
How to join 4x2 timber?
4x2 timber is usually joined with wood screws or nails. Cut the timber square, line it up and fix it securely. Pre-drilling near the ends helps stop the wood from splitting. For basic frames and stud walls, simple straight joints work just fine.
What is 4x2 timber in mm?
4x2 timber is commonly supplied as 100x47mm. The finished, planed size is usually around 95x45mm. Both sizes refer to the same timber section and are used interchangeably on site.
How much is 4x2 timber?
Prices for 4x2 treated timber typically start from around £4.50 per length. Prices change by length and stock, so always check the latest price on the Sheet Materials Wholesale website.
What size screws for 4x2 timber?
For most projects, 4x2 timber is fixed using 70mm to 100mm wood screws. The exact length depends on what you are fixing into it and whether you are joining timber to timber or timber to another material.
Where to buy 4x2 treated timber?
You can buy 4x2 treated timber online from Sheet Materials Wholesale. Order directly from the website and get delivery to the site or home anywhere in the UK.
Our C24 graded 4×2 timber that stays straight and strong, it is kiln dried and minimises movement. The pressure treatment resists rot and pests. It comes from a slow-grown softwood, which means a smoother finish, excellent stability and robust load performance.
Our C24 graded 4×2 timber that stays straight and strong, it is kiln dried and minimises movement. The pressure treatment resists rot and pests. It comes from a slow-grown softwood, which means a smoother finish, excellent stability and robust load performance.
Our C24 graded 4×2 timber that stays straight and strong, it is kiln dried and minimises movement. The pressure treatment resists rot and pests. It comes from a slow-grown softwood, which means a smoother finish, excellent stability and robust load performance.
