Fences & Picket Fencing
Everything you need to build a fence — from planning permission and neighbour notification through to post depth, timber grades and fixings.
Planning & Regulations
Boundary with neighbour
In most jurisdictions you may erect a fence on the boundary line. Notify your neighbour as a courtesy before work begins.
Boundary with road
Rules vary by location. Open, lightweight structures up to 1 m are generally permitted development. Solid fences and visibility splays: stricter controls apply.
Solid screen / wind break
Allowed heights without consent vary by country and municipality — a figure like 2 m (with a lower limit near a road or boundary) is only a common example (e.g. UK permitted development), not a universal rule. Always confirm the height limit, and any neighbour-notification rules, with your local authority.
Boundary position
Confirm the legal boundary line before installation. A fence must not encroach on a neighbour's land. Check title deeds or land registry documents.
Fence Types
| Type | Height | Use | Notes |
|---|---|---|---|
| Picket fence | 900–1,200 mm | Garden, decorative boundary | 48 mm pickets, 30–50 mm gaps |
| Close-board fence | 1,200–1,800 mm | Privacy, garden boundary | Solid or 5 mm gap between boards |
| Slatted fence | 900–1,800 mm | Contemporary, semi-transparent | 20–50 mm gap between slats |
| Horizontal-board fence | 900–1,800 mm | Modern, clean lines | Boards run lengthwise, fixed straight to posts — see below |
| Post and wire / rail fence | 800–1,200 mm | Boundary marking, paddock | Cheapest, lowest maintenance |
| Ranch rail fence | 800–1,000 mm | Decorative / rustic | Open and economical; posts still need proper foundations |
Horizontal (“sidelying”) board fences
In a horizontal fence the boards run lengthwise between posts, screwed straight to the post faces — there are no separate rails. The look is modern, but the build has two rules of its own:
- Shorter post spacing. Every board spans post-to-post with no rail to help, so keep posts at 1.8–2.0 m centres (not the usual 2.4 m) or the boards sag over time.
- Leave a gap between boards. A 5–10 mm gap lets boards swell and shrink with moisture and lets air dry the faces. Butted-tight boards trap water and cup.
- Screws: 2 per board per post — a horizontal fence uses noticeably more screws than a vertical one.
- Count rows, not boards: rows = fence height ÷ (board width + gap). A 1,800 mm fence with 120+10 mm boards needs 14 rows.
Materials & Timber Grades
Timber treatment classes for outdoor use
All timber used outdoors must be treated to the correct use classⓘuse classEuropean timber use classes (EN 335) define the level of treatment required based on exposure to moisture and soil contact. Use class 4 covers ground contact; use class 3 covers above-ground exterior exposure.. Using the wrong treatment class is the most common cause of fence post rot.
Ground and concrete contact. Mandatory for all posts set in the ground. Typically pressure-impregnated with preservative (green or brown tint).
Above ground, fully exposed with trapped moisture risk. Used for rails (stringers) and cladding boards. Withstands weather exposure.
Above ground, fully exposed but with rapid runoff. Minimum for fence boards — use UC3b for longer service life.
Typical Dimensions
| Component | Section | Treatment | Length |
|---|---|---|---|
| Post | 75×75 or 100×100 mm | UC4 | 2.4–3.0 m (depending on fence height) |
| Rail (stringer) | 47×100 mm | UC3b | Cut to panel width |
| Picket board | 28×70 or 28×120 mm | UC3b | 900–1,200 mm |
| Close-board / feather-edge | 22×125 or 22×150 mm | UC3b | 1,800 mm standard |
| Screws | Hot-dip galvanised 4.0×50 mm | — | Never use uncoated steel outdoors |
Frost Depth & Post Setting Depth
The most common fencing mistake is posts set too shallow. Frost heaveⓘFrost heaveFrost expansion in the ground that pushes posts upward and out of position. The problem is worsened by water collecting around the post base and freezing. destroys fences whose posts are not set below the frost depth for the region.
| Climate Zone | Typical Frost Depth | Recommended Post Depth |
|---|---|---|
| Mild coastal (e.g. southern UK, Atlantic coast) | 0–300 mm | 450–600 mm |
| Temperate inland (central Europe, northern UK) | 300–600 mm | 600–750 mm |
| Cold continental (northern/eastern Europe) | 600–1,000 mm | 800–1,000 mm |
| Subarctic (Scandinavia inland, Canada) | 1,000–2,000 mm | 1,100–1,500 mm |
A simple rule of thumb: set posts to a minimum depth of 1/3 of the total post length, or to below local frost depth — whichever is greater.
Concrete Surround
- Hole diameter: 3× post width (100 mm post → 300 mm hole)
- Standard post: approx. 1.5 bags of 25 kg concrete mix. Corner/gate post: 2–2.5 bags
- Place 150 mm of gravel or crushed stone in the base for drainage — never pour concrete against the bottom
- Taper the concrete surface away from the post to shed water
- Curing time: at least 24–48 hours before applying any load
Bolt-down / Spike Post Supports
- Steel spike driven into ground; post slots into the bracket above soil
- Advantage: post end does not contact the soil — no rot at the base
- Typical drive depth: approx. 500–600 mm
- Maximum recommended fence height: 1,200 mm using spike supports
- Not suitable in loose soil or frost-susceptible ground
Step by Step
Measure the run and mark post positions. Always start and end with a post.
- Post spacing: 2.0–2.4 m centres for picket fencing. Close-board (high wind load): max 2.0 m centres.
- Run a taut string line between corner posts as a reference
- Verify the fence does not cross the legal boundary — consult the title plan if in doubt
- Notify your neighbour before installing a solid fence over 1,200 mm or where they may be affected
Depth is the most critical step — shallow posts are the leading cause of fence failure.
- Use a post-hole borer (manual, or a rented petrol auger) — produces clean holes without disturbing the sides
- Place 100 mm of gravel in the base for drainage
- Set post, check plumb in both directions with a spirit level
- Pour concrete and brace the post until set (use temporary wedges and support boards)
- Crown the concrete slightly away from the post to direct water away
Rails are the horizontal members that the cladding boards fix to.
- Two rails for fences up to 1,500 mm high; three rails for taller fences
- Top rail: 100–150 mm from the top. Bottom rail: 100–150 mm from the ground
- Check rails are level with a spirit level
- Fix with at least 2 hot-dip galvanised screws per joint, or use proprietary rail brackets
- Start from a corner and work along the fence
- Use a spacer block for consistent gap width between boards
- Check vertical with a spirit level every 3rd or 4th board
- Use a minimum 2 screws per board per rail (4.0×50 mm hot-dip galvanised)
- Avoid screwing into end grain — poor holding strength and higher rot risk
- Pointed picket tops: cut at 45° or use a jigsaw for a curved profile
- Apply stain, oil or paint to all surfaces — including cut faces and end grain
- End grain (tops of boards and posts) absorbs water most readily — apply two coats there
- Pressure-treated timber can be painted after 6–12 months (allow to dry thoroughly)
- Maintenance: re-apply a coat every 3–5 years depending on exposure
- Inspect post bases annually — algae growth and soil packed against the post accelerate decay
Materials per Linear Metre
Common Mistakes
Calculate Fence Materials
Enter the fence length, height and style — get a full material list including posts, rails, boards, screws and concrete.
Open Fence CalculatorTools you'll need
The kit this job actually calls for, and whether it's worth buying or renting for one weekend.
- Post hole digger
Digs a narrow, deep hole — much better than a spade for posts.
Buy 25–60 € - Spirit level
Get a 1.2 m one — short levels lie on long runs.
Buy 15–60 € - String line and pegs
One line end to end, or the fence will wander visibly.
Buy 5–15 € - Shovel and spade
A square shovel for mixing and moving, a spade for digging.
Buy 15–40 € - Wheelbarrow
A builder's barrow with a pneumatic tyre, not a garden one.
Buy 50–120 € - Cordless drill/driver
The one power tool every job on this site needs.
Buy 60–200 € - Hand saw
For the cuts not worth setting up a power tool for.
Buy 12–30 € - Tape measure
A 5 m or 8 m tape with a locking blade.
Buy 8–20 € - Safety glasses, gloves and dust mask
Silica dust from tile, block and render is the real hazard on these jobs — an FFP3 mask, not a paper one.
Buy 15–40 €
Prices are indicative for DIY-grade tools and vary a lot by brand and region — treat them as a budgeting starting point, not a quote. Rental rates are per day from a typical tool rental shop.
Frequently asked questions
How deep should fence posts be set?
A common rule of thumb is at least 1/3 of the total post length in the ground. In frost-prone climates the post should also go below the local frost line — and that depth varies a lot by region (often quoted around 36–48" / ~0.9–1.2 m in parts of the US, but it can be deeper, and elsewhere it is set by local frost data). Use your local frost depth rather than a fixed figure, and set corner and gate posts deeper.
What wood is best for fence posts?
Use pressure-treated (PT) lumber rated for ground contact (UC4A or UC4B). Cedar and redwood can be used above-ground but PT is required for posts in the soil.
Do I need a permit to build a fence?
Many jurisdictions allow fences under 6 ft without a permit, but regulations vary. Always check local zoning ordinances and HOA rules and consider notifying neighbors before building.
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