UC4 Square Timber Fence Posts, Kiln Dried, Green or Brown Treated, 50mm to 200mm, 1.5m to 3m

On a closeboard, panel or post-and-rail fence, the posts stand in wet soil for years while everything else hangs off them. These square pine fence posts are kiln dried and then pressure treated to UC4, the use class for timber in ground contact, so you can set them straight into the ground. They suit fencing contractors, landscapers, smallholders and homeowners who want a straightforward, rough-sawn post. Choose green or brown treatment, in sections from 50x50mm to 200x200mm and lengths from 1.5m to 3.0m, sold individually so you order exactly what your run needs.

Why it works

Kiln dried before it's treated

The pine is dried in a kiln before treatment, so the preservative goes into timber that is ready to take it. That supports the deep penetration the treatment is designed to give, rather than a coating that sits near the surface.

UC4 pressure treatment for ground contact

Use class 4 covers timber that sits in the ground. Pressure treatment drives preservative deep into the post to protect against fungal decay, insect attack and water-borne rot, which is exactly where a post is most exposed: at and just below ground level. The expected service life in ground contact is around 15 years. That is an expectation, not a guarantee.

Rough sawn, square section

The surface is left rough sawn rather than planed. It's a working finish suited to fencing, gate posts and framing, not a smooth joinery face, so expect texture if you stain or paint it later.

• Kiln dried, then pressure treated to UC4
• Around 15 years expected life in ground contact

Where it's used

Most of these posts go into garden and boundary fencing: closeboard, panel and post-and-rail. The larger 150x150mm, 175x175mm and 200x200mm sections are used as gate posts where you need to hang a heavier gate. Beyond fencing, the same posts work as pergola uprights, raised bed corners, general framing and decking supports, and for livestock and paddock fencing on farms and smallholdings.

Specifications

Choosing the right option

Start with length. Plan to bury roughly a quarter to a third of the post, so add that to your finished fence height. A 2.4m post typically gives a 1.8m (6ft) fence with 600mm in the ground.

Next, pick the section. The 150x150mm to 200x200mm posts are the ones to choose for gate posts carrying heavier gates. The 50x50mm section is the lightest in the range; the spec table lists treatment for the range as UC4 and UC3, so if you need certified UC4 on 50mm posts, please confirm with us before ordering.

Finally, colour. Green-treated posts start green and weather to honey brown, then silvery grey. Brown-treated posts start brown and also silver with age. Brown comes in fewer sizes, so check the table first.

Installation, use & care

Bury roughly a quarter to a third of each post and set it in post mix or compacted hardcore. You can cut the posts with a circular saw, chainsaw or handsaw. Any freshly cut surface must be treated with a wood preservative such as an end-grain preserver, especially the end going into the ground. Once the treatment colour has faded, you can stain or paint the posts. An annual coat of stain or preservative keeps the colour.

FAQ

How much of the post should go in the ground?

As a general rule, bury roughly a quarter to a third of the post and set it in post mix or compacted hardcore. For a 1.8m (6ft) fence, a 2.4m post with 600mm in the ground is the usual choice.

Can I cut the posts to length?

Yes. A circular saw, chainsaw or handsaw will do it. Treat every freshly cut surface with a wood preservative such as an end-grain preserver, and pay particular attention to any cut end that will go into the ground.

Will the green or brown colour last?

No, it weathers. Green posts go honey brown and then silvery grey; brown posts also silver with age. If you want to hold a colour, stain or paint once the treatment colour fades and apply a stain or preservative each year.

Which size should I use for a gate post?

For hanging heavier gates, use one of the larger sections: 150x150mm, 175x175mm or 200x200mm. These are available in green only, with 150x150mm at 2.4m or 3.0m and the other two at 3.0m.

Ordering & delivery

Posts are priced per post as listed: choose colour, section and length, then add the quantity you need. Delivery is to UK mainland addresses. Longer posts travel on a pallet or by kerbside service. Your lead time is confirmed at checkout or on your order confirmation.