Fence Posts & Rails

Unleash Your Garden's Potential with Fence Posts & Rails

If you're planning to upgrade your garden, secure a boundary, or create a private retreat, the backbone of any good fence is the post. Fence posts and rails might sound basic, but choosing the right type, size, and finish makes the difference between a fence that stands proud for decades and one that leans, rots, or needs constant repair. This guide walks you through the most popular post types—timber and concrete—explains common sizes like 6' and 8' posts, and helps you match posts to rails and panels so your fence looks great and lasts longer.

Why the Right Fence Post Matters

Think of fence posts as the skeleton of your fence. They carry the load, resist wind and soil movement, and anchor rails and panels in place. A flimsy post and everything else becomes cosmetic; a well-chosen post makes the rest of the build almost effortless. When you learn what to look for—treatment level, cross section, and length—you save time, money, and hassle down the line.

Types of Fence Posts: Timber vs Concrete

Timber Posts — Treated and Planed

Timber posts are the go-to for many gardens because they’re easy to work with, look natural, and accept screws and fixtures without special tools. Popular options include UC4 incised treated posts, often finished in a forest green stain, and planed posts with smooth faces for a cleaner look. For example, a common timber post comes in a 6' length with a 4" x 4" cross section—sturdy enough for most garden panels and rails.

Lightweight Concrete Posts

Concrete posts offer long-term durability and are ideal where timber might struggle—soggy soil, heavy gates, or exposed, windy locations. Modern lightweight concrete posts are easier to handle than old solid stone posts while still giving great strength. An 8' lightweight concrete post with roughly a 4" x 3" cross section is a classic choice when you need extra longevity and stability.

Planed vs Incised: What’s the Difference?

Planed posts are smoothed after cutting and present a refined finish that makes paint and stain go on evenly. Incised posts have small cuts made into the surface to help preservative soak deeper into the wood—ideal for UC4 ground-contact applications. If you want a neat finish plus long-term rot resistance, look for a planed, UC4-incised option or a planed post that has also been pressure treated.

Popular Post Sizes and What They Mean

Size matters. The industry often lists posts by overall length and cross-sectional dimensions, such as “6' x 4 x 4” meaning a 6-foot-long post with roughly a 4" by 4" face. Here are some typical options and the uses they fit best:

- 6' x 4" x 4": A versatile post for standard garden panels and most boundary fences.

- 6' x 3" x 3": Lighter-duty posts suitable for smaller panels, picket fences, and decorative boundaries.

- 7' x 3" x 3" or 7' x 4" x 4": Add extra height for taller panels or where a bit more ground embedment is required.

- 8' x 4" x 3": Often a concrete post option—excellent for exposed sites or where you need a post with a slender profile but solid mass.

Choosing the right profile depends on the weight of the panels or rails you plan to use and the conditions your fence will face.

How Deep Should You Set a Post?

A common rule of thumb is to bury roughly one-third of the post’s length. So a 6' post typically sits about 2' in the ground with 4' above ground; a 7' post takes around 2'4" burial; an 8' post might need 2'8" buried. For high winds or heavy gates, consider deeper holes or concrete footings. Always allow for a gravel base (about 6" deep) to aid drainage and avoid trapped moisture at the base of a wooden post.

Matching Posts to Rails and Panels

Not all posts pair well with all rails. A 4" x 4" timber post provides a solid surface to screw rails directly, whereas a 3" x 3" post might be better suited for thinner rails or fence panels that attach with brackets. Timber posts tend to accept screws and nails easily; concrete posts need special brackets, and some are designed with slots or pins to accept rails directly. When buying, check whether the post is intended for fence panels, featheredge boards, or rails—compatibility saves a lot of fitting headaches.

Installation Tips for a Strong, Long-Lasting Fence

Installing posts properly is half the job. Start by siting posts on firm ground, mark out a straight line with a string, and dig holes to the correct depth—typically 12" to 18" in diameter depending on the post size. Use a 6" layer of compacted gravel at the bottom for drainage, then place the post plumb and backfill with concrete or well-compacted rubble. If you use timber posts in concrete, slope the concrete away from the post to prevent water pooling against the wood. Finally, leave a small gap between the ground and the first rail or panel bottom to avoid moisture contact—about 2" is a good rule.

Maintaining Timber and Concrete Posts

Maintenance keeps posts standing long-term. For timber, ensure ends are sealed and apply exterior wood preservative every few years, especially on cuts or notches made during installation. Forest green ripples through many timber posts as a factory finish—it's handy because it masks stains and gives built-in protection—yet periodic oil or stain refresh keeps them looking sharp. Concrete posts need surprisingly little care, but check for chips or hairline cracks after freeze-thaw cycles and repair as needed with a small cement patch.

Cost vs Longevity: What to Expect

Timber posts are generally cheaper upfront and easier to handle, while concrete posts cost more but pay back with long-term resilience. When you factor in replacement cycles, a properly treated 6' x 4" x 4" timber post might last 10–20 years in good conditions, whereas a concrete post can last several decades if installed correctly. Think of timber as the flexible, easy-to-change option and concrete as the set-it-and-forget-it solution.

Spotlight on Popular Product Types

Looking at today's market, a few product styles keep appearing because they balance cost, durability, and ease of use. Here are some examples framed in familiar terms so you can compare quickly:

- 6' x 4" x 4" Forest Green UC4 Incised Timber Post: A classic choice for garden panels; the UC4 incised treatment is designed for ground contact and offers excellent rot resistance. Forest green finish blends into foliage for a discreet boundary.

- 6' x 3" x 3" Forest Green UC4 Incised Timber Post: Lighter but still treated for the ground; ideal for lower panels or picket-style fencing where the massive strength of a 4" post isn’t required.

- 7' x 3" x 3" or 7' x 4" x 4" Timber Posts: These give extra above-ground height for taller panels or gates and increase the buried length for stability—useful on sloping grounds where a little extra post length ensures a proper fit.

- 5'11" x 2.7" x 2.7" & 4'11" x 2.7" x 2.7" Planed Posts: These planed posts have a smooth finish at slightly below 6' and 5' heights—great for neat, painted fences or decorative garden partitions where looks matter.

- 8' x 4" x 3" Lightweight Concrete Post: A great pick if you want the longevity of concrete but without the brutal weight; use these where timber posts might fail, such as with heavy gates or exposed garden edges.

Practical Tips for Choosing the Right Post

Ask yourself simple questions: How tall do I want the visible fence to be? Will there be a gate? Is your soil wet, chalky, or stable? Do you want a painted finish or a natural wood look? For gates and heavy loads pick thicker posts (4" x 4" or concrete options), for decorative boundaries 3" x 3" timber is often enough. If kids and pets are a factor, choose posts that allow close-fitted panels and secure fixings.

Eco and Safety Considerations

Timber from certified sources is a responsible choice; look for chain-of-custody labels or recycled timber if you want to lower your environmental impact. Treated timbers use preservatives to prevent rot—these are safe when used as intended, but avoid burning treated offcuts. For concrete, lightweight options still have a lower long-term replacement footprint because they last longer and require fewer renewals.

Common Mistakes to Avoid

Avoid these traps: setting posts too shallow; not allowing for drainage; buying the cheapest untreated timber for ground contact; and assuming all posts are the same size even when labelled similarly. Also, don’t mix post materials carelessly—different expansion rates and fixing methods can shorten the life of your fence if timber rails are attached to concrete posts without proper brackets.

Where to Buy and Compare Options

When shopping, compare treated versus planed finishes, check the cross section (3" x 3" vs 4" x 4"), and confirm the length you actually need. Many suppliers offer finished colours such as forest green or planed timber ready for staining. If you want to compare prices and features side-by-side, look for a comparison listing that shows product specs, treatments, and typical uses so you can make an informed pick without visiting ten different shops.

Conclusion

Choosing the right fence post involves balancing strength, appearance, and environment. Whether you prefer the natural look of a planed timber post, the deep protection of a UC4 incised post, or the low-maintenance durability of lightweight concrete, there's a solution to suit your garden. Consider height, cross section, and ground conditions first, then match rails and panels to those choices. With a little planning, you can build a fence that looks good, performs reliably, and stays put for years.