The standard paling fence
A timber paling fence is posts set in concrete, rails nailed between them, and palings nailed to the rails. The count is straightforward once the bay length is fixed. Posts are the length divided by the bay, plus one for the end. Rails are the length times the number of rail lines. Palings are the length divided by the width each paling actually covers.
palings = length ÷ (paling width − overlap) × 1.03
The overlap is the number that catches people out. Butt-joined 100 mm palings cover 100 mm each, so ten per metre. Lapped palings overlap their neighbours by about 25 mm, so each one only covers 75 mm and you need thirteen per metre, a third more timber for a fence that shrinks without leaving gaps.
| Paling | Style | Cover | Per metre | 24 m fence |
|---|---|---|---|---|
| 100 mm | Butt | 100 mm | 10.0 | 248 |
| 100 mm | Lapped 25 | 75 mm | 13.3 | 330 |
| 150 mm | Butt | 150 mm | 6.7 | 165 |
| 150 mm | Lapped 25 | 125 mm | 8.0 | 198 |
Bays, rails and posts
Two point four metres is the standard bay because rails come in 2.4 and 4.8 m lengths, so a 4.8 m rail spans two bays and joins on a post. Long runs often go to 2.7 m to save a post in every ten metres; beyond 3 m the rails sag and the fence looks tired within a couple of years. A 1.8 m fence takes three rails: two is enough to about 1.5 m, but at 1.8 the palings cup between the rails and the whole panel drums in a north wind. Posts are 100 × 100 or 125 × 75 treated pine, or 100 × 50 for a light fence, set 600 mm into the ground, so a 1.8 m fence uses 2.4 m posts. Gate posts get a bigger hole, a deeper hole, and often a heavier post.
Concrete
A 300 mm hole 600 mm deep with a 100 × 100 post in it takes about 0.04 m³ of concrete once the post volume comes out, which is five 20 kg bags. Fifty-five bags for eleven posts is a tonne of concrete to mix by hand, so for a long run consider a premix delivery or a tow-behind mixer. The post hole calculator lets you change the hole size for gate posts and soft ground.
Fixings and finishing
Palings are fixed with two galvanised nails at every rail, so a 1.8 m fence with three rails uses six nails per paling. Twist-shank or ring-shank nails hold better than plain. Rails are fixed to posts with two or three nails at each end, or with galvanised screws if the posts are hardwood. Leave the palings a few millimetres above the plinth. If you plan to stain or paint, do it before the fence goes up if you can; painting 300 palings in place is a long weekend.
Boundary fences
In Victoria a fence on a boundary between two properties is normally a shared cost under the Fences Act, and there is a notice process for agreeing the type of fence and splitting the bill. A standard 1.8 m paling fence is what the Act calls a sufficient dividing fence in most suburbs. Fences over 2 m, front fences over 1.5 m, and fences near a corner may need a permit. Check with council before you set the posts.
Worked example
A 24 m side boundary fence, 1.8 m high, in 2.4 m bays with three rails, 100 mm palings butted, with a plinth. Ten bays, eleven posts at 2.4 m. Rails 3 × 24 × 1.05 = 76 m, which is sixteen 4.8 m lengths. Palings 24 ÷ 0.1 × 1.03 = 248. Plinth 25 m. Concrete five bags a post, 55 bags. Nails about 1,560.
Common questions
How many palings per metre?
Ten 100 mm palings butted, about 13 lapped. 150 mm palings: 6.7 butted, 8 lapped.
How far apart are fence posts?
2.4 m standard, 2.7 m on long runs. Not more than 3 m.
How many rails on a 1.8 m fence?
Three. Two is enough only up to about 1.5 m.
How much concrete per post?
About five 20 kg bags for a 300 × 600 hole. Gate posts about twelve.
Quantities only. Fence heights, boundary rules and permits vary by council; check before you build.