Picket Fencing Installation

Quick Answer: Picket fences in the UK are typically built from FSC-certified Class 4 pressure-treated softwood pickets fixed to two horizontal arris rails, supported on 75 × 75 mm posts at 1.8m or 2.4m centres set 600mm into 1:6 ballast or postcrete. Maximum height for a front boundary without planning permission is 1m where it adjoins a highway used by vehicles, and 2m elsewhere (Town and Country Planning General Permitted Development Order 2015 Schedule 2 Part 2 Class A). Pickets should be set 25–50mm above ground to avoid wicking and rot.

Summary

A picket fence is the simplest joinery-based boundary fence and the easiest to get wrong. The picket itself does almost nothing structurally — the fence's stiffness comes from the posts and the two rails between them. Most early failures (sagging, leaning, individual pickets dropping off) trace back to either an undersized post embedment or fixing the picket to a single rail rather than two. The look depends on consistent picket-to-picket spacing, level top edges along long runs, and clean post tops; sloppy execution shows clearly because the fence is at eye level and front-of-house.

Tradespeople meet picket fencing on three jobs: front boundaries on character properties (Victorian terraces, period rural cottages), garden subdivisions where a low decorative line is wanted, and around children's play areas. The same construction works for all three; only height and picket profile change. The buyer is almost always the homeowner, often pricing against off-the-peg ranch panels, so the labour-vs-panel cost conversation comes up early.

UK material practice has converged on Use Class 4 (UC4) pressure-treated softwood — typically incised European redwood with copper-azole or alkaline copper quaternary preservative. Pre-painted or oiled pickets last longer above ground but do nothing for the post that sits in soil; the post is always the first part to fail. Composite and PVC pickets exist but cost two to four times the price of treated timber and are rarely specified outside coastal or heritage contexts.

Key Facts

Quick Reference Table

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Fence height (above ground) Post size Post length Embedment depth Post centres Rails per panel
600mm (2 ft) 75 × 75 mm 1.2 m 600 mm 1.83 m 2
900mm (3 ft) 75 × 75 mm 1.5 m 600 mm 1.83 m 2
1.05 m (3.5 ft) 75 × 75 mm 1.65 m 600 mm 1.83 m 2
1.2 m (4 ft) 75 × 75 mm 1.8 m 600 mm 1.83 or 2.44 m 2
1.35 m (4.5 ft) 100 × 100 mm 2.1 m 750 mm 1.83 m 2–3
1.5 m (5 ft) 100 × 100 mm 2.25 m 750 mm 1.83 m 3
1.8 m (6 ft) 100 × 100 mm 2.55 m 750 mm 1.83 m 3

Detailed Guidance

Setting Out and Boundary Lines

Picket fence work begins with the boundary, not the fence. Get the boundary wrong and the fence either encroaches on a neighbour or sits short on the homeowner's property. For Land Registry-registered title plans, the line marked is indicative only — the registered legal boundary follows the physical boundary that existed when the title was first registered. For most domestic jobs, the fence line is taken from existing posts, kerb edges, or party wall corners by mutual agreement with neighbours.

If a fence is being replaced on the line of an existing one, photograph the existing fence and post positions before removal. If the project is a new boundary or relocates an existing one, get a written acceptance from the affected neighbour. Verbal agreement disappears the moment a buyer changes hands.

The convention is that the "good side" — the picket face, with no rails or post mortices visible — faces away from the property. This is custom rather than law. Some homeowners prefer to face the good side to their own garden; others split the difference with double-sided pickets (more expensive, neither face shows the rails). State the orientation in writing on the quote to avoid disputes.

Post Setting

Mark out post positions with string line and pegs. Standard practice is to dig the end posts first, set them plumb, run a string line at the top, and set the intermediate posts to that line. This guarantees the top of the rails reads straight along the length of the fence. The alternative — digging all post holes first and setting one by one — risks cumulative drift across long runs.

Hole dimensions: 200mm diameter, 600mm deep for fences up to 1.2m exposed; 250mm diameter, 750mm deep for taller fences. A petrol auger speeds work over 6+ posts; a clamshell post-hole digger is sufficient for 4 or fewer. Hand-digging in heavy clay is hard work and the gain in hole tolerance is small.

For postcrete: pour 75–100 mm of clean stone in the hole bottom for drainage, position the post, plumb it, fill the void with water (50% of the hole volume), tip in postcrete, allow to set 10 minutes. The mix expands slightly as it sets, locking the post in place. For 1:6 ballast: pour drainage stone, position post, mix ballast and cement 6:1 with just enough water to make a stiff mortar, fill in 200mm lifts and tamp. Curing takes 24 hours before rail fixing.

The post head should sit 150–200mm above the picket top to allow a post cap to be fitted clear of the picket line. Posts left flush with the picket top wick water and rot prematurely.

Rail Fixing

Two rails per panel is non-negotiable for fences over 600mm. A single-rail picket fence fails within a season — the unsupported picket pivots on the rail and fixings work loose.

Top rail: 200–250 mm below the picket top. Bottom rail: 100–150 mm above the picket bottom.

For mortice-and-tenon construction, mortices are pre-cut in the post (factory-machined posts available with paired mortices), and the rail tenon is shaped to fit. This is the strongest joint and the traditional joinery approach. Galvanised "U" brackets bolted to the post face are the modern shortcut and acceptable for most domestic work — faster, no precise marking out, but visually noisier.

Whichever fixing method, the rail joint between adjacent panels must occur at a post, not mid-bay. Splicing rails between posts halves the panel stiffness.

Picket Fixing

Pickets are fixed to the rails, never to the posts. The picket spacing jig — a 50–75 mm scrap of timber the same width as the desired gap — sits between pickets to set the gap. Work from one post toward the next, checking plumb every 4–5 pickets and adjusting the jig pressure if drift develops.

Two fixings per rail per picket: one ring shank nail or screw 25mm in from each long edge of the picket. A single central fixing allows the picket to rotate and split.

A2 stainless steel fixings are the only correct choice for new treated softwood. Modern UK timber preservatives (copper-azole, ACQ) corrode galvanised steel within 2–5 years; the rust trail down each picket is the classic giveaway of a fence built with the wrong fixings. Stainless ring shank nails cost roughly twice the price of galvanised but the fence outlives the difference five times over.

For the picket top: pointed pickets shed rain best. Square or rounded tops trap water in the end grain unless capped. If using square-top pickets, paint or oil the top end grain before fixing — every coat past the first one wears off in the first weather cycle.

Levelling Across Sloping Ground

Two finishing options on slopes:

Stepped — each panel is horizontal, with a step down at each post. Looks more formal, suits Victorian or cottage settings, easier to build cleanly. Requires the rails to be cut to length per panel.

Raked — each panel rakes parallel to the slope, picket tops follow the ground. Looks more relaxed, suits rural settings, faster to fix because the rails run uncut along the full slope. Works best on consistent slopes; mixed slopes look poor when raked.

The stepped option is the safer specification. Get the slope wrong on a raked fence and the whole run looks drunk; on a stepped fence the worst that happens is one step is taller than the others, which reads as deliberate.

Frequently Asked Questions

How much should I charge to install a picket fence?

Typical UK rates in 2026 are £45–£75 per linear metre for a 900mm picket fence using treated softwood, supply and installation. London and the south-east trends toward £75–£110 per linear metre. Materials are roughly 35–45% of the supply-and-fit price; the rest is labour and post-setting consumables. A two-trade team installs 12–20 metres of straight-run picket fence in an eight-hour day on level ground; expect 30–40% productivity loss on slopes, around obstacles, or where existing fence removal is required. See pricing methodology for trade quotes for marking up materials and labour consistently.

Do I need planning permission for a picket fence?

Not normally for a fence under 1m where it adjoins a highway used by vehicles, or under 2m elsewhere — these are permitted under the Town and Country Planning General Permitted Development Order 2015. Permission is required for: any height in a Conservation Area where Article 4 directions apply, listed buildings, fences over the limits, and where the property has had its permitted development rights previously removed. See the scope of permitted development rights for boundary works for related boundary works.

How long does a treated softwood picket fence last?

Posts (the limiting component) typically fail at 12–18 years where set in concrete, slightly less in ballast. Posts will last longer if the post head is shed-shaped or capped, the post sits clear of bedding planters and grass clippings, and the timber was incised during preservative treatment. Pickets and rails outlast the posts; the common repair pattern is to replace failed posts and reuse pickets. Concrete spur posts (a short concrete reinforcement bolted to a failing timber post) extend post life by 5–10 years on jobs where full replacement is not warranted.

Can I just nail pickets to the top and bottom of one rail?

No. Two rails are needed for fences over 600mm — a single rail fence pivots around the fixing line and fails fast. The cost of the second rail and the labour to fit it is small compared to a fence rebuild.

Regulations & Standards