Colorbond Gate Sizes: A Practical Sydney Guide

Rick

Sep 30

6 min read

Most people asking about Colorbond gate sizes are really asking one of two questions: will a gate fit the gap I have, or how wide does the gap need to be for what I want to get through it. They are different problems, and mixing them up is how a gate ends up too narrow for the trailer or too wide to swing without hitting the garden bed.

The short answer

Colorbond gate heights follow the fence they sit in, so they come in the same set heights as the panels. Widths are the flexible part: a gate leaf is built or cut to suit your opening, within the practical limits of what a single leaf can carry without sagging. Beyond roughly three metres of opening, you are almost always looking at a double gate rather than one very wide leaf.

Heights: the gate matches the fence

A Colorbond gate is designed to read as part of the fence line, so its height is set by the panel height either side of it. The heights commonly available through Australian suppliers run in steps, with 1.8 metres the standard for a back or side boundary and lower heights used at the front. Exact stock heights vary by supplier and by the sheet profile, so confirm before you order.

Two things worth knowing about gate height. First, a gate is usually set slightly higher off the ground than the fence, because it has to swing clear of paving, gravel and any ground movement. Second, height rules for front boundaries are set by your council, not by the material, so the height decision on a street-facing gate is a planning question before it is a product question. We cover this in more detail in our guide to Colorbond fence heights in Sydney.

Widths: single gates

A single Colorbond gate covers everything from a narrow pedestrian opening to a single vehicle. What you should be sizing for is the widest thing that has to pass through, plus room for your hands and for the thing not being perfectly centred.

Pedestrian and side access: wide enough for a person is not the test. A wheelie bin, a mower, a wheelbarrow or a bike trailer is. Side access openings that are sized for a person alone get regretted within a year.
Single vehicle: a single leaf can span a car-width opening, but a wide single leaf puts a lot of leverage on the hinge post, and that is what causes drop and drag over time.
The practical ceiling: the wider one leaf gets, the heavier the frame, hinges and posts have to be to hold it square. Past about three metres, splitting it into two leaves is usually both cheaper and more reliable.

The same clearance logic applies to timber side gates, and the measuring section of our timber side gate guide is worth a read even if you are going with steel.

Widths: double and driveway gates

For a driveway you are sizing the opening first and the leaves second. Two leaves share the span, so each one is lighter, hangs straighter and puts less strain on its post than a single gate covering the same gap.

Things that push a driveway opening wider than people expect: a gate that sits close to the street with no room to swing in, a driveway that curves as it meets the kerb, brick piers that eat into the clear opening, and towing anything. If you tow a boat or a caravan, measure that, not the car. There is a fuller treatment of swing versus slide, automation allowances and post sizing in our Colorbond driveway gate guide.

The opening is not the gate

This is the single most common measuring mistake. The gate leaf is always smaller than the opening it sits in, because it needs:

a gap on the hinge side for the hinge hardware and for the leaf to swing without binding
a gap on the latch side for the latch and for the leaf to close without scraping
clearance underneath so the gate does not catch on paving, gravel, grass or a driveway crossfall
a small allowance for the posts themselves being plumb but not perfectly parallel on an old fence line

So when a supplier quotes a gate size, check whether that is the leaf size or the opening size. A gate ordered at the opening dimension will not close.

How to measure your opening properly

Measure between the posts at the top, the middle and the bottom, and use the smallest of the three. Old posts lean.
Measure the drop across the opening. If one side is lower, the gate has to clear the high point and will show a gap at the low point.
Check what the gate swings over for its full arc, not just where it sits now: paving lips, garden edging, a rising driveway, a downpipe.
Decide which way it must open before you measure hinge clearances. Inward, outward, and which side, all change what fits.
Note what has to pass through it, measured at its widest point including mirrors, handles and trailer guards.

Posts and footings scale with the gate

Gate size is not only a gate question. A gate is a lever, and everything it does goes into the hinge post and its footing. A wider or taller leaf needs a heavier post section and a deeper, wider footing than the fence posts either side of it, and it needs the concrete properly cured before the gate is hung.

Where Colorbond gates sag, it is far more often the post and footing than the gate itself. If you are matching a new gate into an existing fence, the existing post is worth assessing honestly rather than assuming it will do. General material and installation background is in our Colorbond fencing guide, and the range of gates we build is covered in our Sydney gates guide.

Slope, clearance and ground movement

On a sloping block a gate cannot be raked the way a fence panel can, because it has to swing. That means the gate stays square and the ground falls away from it, so you either accept a growing gap at the low end, step the fence line so the gate sits in a level section, or build up the ground under the swing. Deciding this before the posts go in is much easier than after.

Sydney's reactive clay soils also move seasonally, so a gate set with almost no ground clearance in winter can drag in summer. A little more clearance than looks necessary is the safer setting.

Pool gates are a separate question

If the gate forms part of a swimming pool barrier, size is only one of several requirements that apply, and they cover things like the direction of swing, self-closing and self-latching hardware, latch position and anything climbable near the barrier. These requirements are enforced by your council and are not something to take from a general article. Check with your local council and the NSW Swimming Pool Register before ordering a gate for a pool barrier.

When a custom gate beats a kit

Kit gates are good value when the opening is a standard size, the posts are new and the ground is level. A made-to-measure gate earns its cost when:

the opening is an odd width because it sits between existing structures
you are fitting into an old fence line with posts that are not square or plumb
the ground falls noticeably across the opening
the gate is unusually wide, tall or heavy, or will later be automated
you want the infill, frame or hardware to match something specific

Frequently asked questions

What is the standard Colorbond gate height?

Gates follow the fence panel heights, and 1.8 metres is the usual choice for a back or side boundary in Sydney. Front gates are often lower, and that choice is generally governed by your council's front boundary rules rather than by what is available.

How wide can a single Colorbond gate be?

Wide single leaves are possible, but the wider and taller a leaf gets, the more load it puts on its hinge post. As a practical rule, once an opening is around three metres or more, two leaves will hang better and stay square longer than one. Your supplier's span limits for the specific frame and hardware should be the deciding factor.

Should I measure the opening or the gate?

Measure the opening, then let whoever builds the gate subtract the hinge, latch and ground clearances. If you order a gate at your opening dimension, it will not fit.

Can I add a Colorbond gate to an existing fence?

Usually yes, but the hinge post normally needs to be upgraded or re-footed. Fence posts are sized for panels, not for the leverage of a swinging gate, and reusing one is the most common reason a new gate starts dropping within a season.

What gap should there be under a Colorbond gate?

Enough that the gate clears the highest point of its swing across the whole arc, with room for seasonal ground movement. The exact figure depends on the surface, the fall across the opening and whether the gate forms part of a pool barrier, where clearance under the gate is a regulated matter to check with your council.

Get the sizes right before anything is ordered

Measuring an opening properly takes ten minutes on site and saves a gate that never closes cleanly. We build and install Colorbond gates across Sydney, from the Sutherland Shire and St George through to the Inner West, Eastern Suburbs and Canterbury-Bankstown, and we handle gate installation into both new and existing fence lines. You can see the full range of fencing we do on our Sydney fencing page, or contact us for a quote and we will measure it up with you.