Colorbond Post Extensions: How to Raise Your Fence Height Without Replacing Posts

One of the most common questions we get at Wallan Fencing and Timber Supply is: "Can I make my existing Colorbond fence taller without replacing all the posts?" The answer is yes — with Colorbond post extensions.

Post extensions are purpose-made steel sleeves that slide over the top of existing C-Channel posts, effectively extending their height. Combined with additional fence rails and sheets, they let you raise a 1.8m fence to 2.1m (or higher) without the cost and disruption of digging out and replacing every post.

When Are Post Extensions the Right Choice?

Post extensions are ideal when:

• You want more privacy. A 1.8m fence is the standard residential height, but many homeowners in Wallan and Mitchell Shire find they want more privacy — particularly on corner blocks or properties near busy roads.
• You're upgrading an existing fence. If the posts are still in good condition but the fence height is no longer adequate, extensions are far more cost-effective than a full replacement.
• You need to meet a new height requirement. Planning requirements or body corporate rules sometimes change. Extensions let you comply without a full rebuild.
• You want to add trellis or lattice above the fence line. Extensions provide the post height needed to support a trellis panel above the solid fence.

How Post Extensions Work

A Colorbond post extension is a C-Channel section that slides over the top of your existing post and is secured with bolts or tek screws. The extension has the same profile as the original post, so fence rails clip in the same way. You then add an additional rail and sheet section above the existing fence line.

The result is a seamless-looking fence at the new height — the join between the original post and the extension is barely visible once the sheets are in place.

What You'll Need

To raise a 1.8m fence to 2.1m using post extensions, you'll need:

• Post extensions — one per post
• Additional fence rails — one extra rail per bay
• Additional fence sheets — the extra 300mm of height per bay
• Post caps — to cap the new top of the extended posts
• Tek screws — to fix the new sheets

We stock all of these at our Wallan yard.

Height Restrictions: Check Before You Build

In Victoria, residential fencing height limits apply. In most residential zones, a fence over 2.0m in height requires a planning permit from Mitchell Shire Council. Before raising your fence height, check the current requirements — or call us and we can point you in the right direction.

Colour Matching

Post extensions are available in Colorbond colours to match your existing fence. If your fence is more than a few years old, the colour may have faded slightly — bring a sample to our yard so we can help you find the closest match.

Available at Wallan Fencing and Timber Supply

We stock Colorbond post extensions at our Wallan yard, with same-day pickup available. We supply homeowners, tradies, and builders across Mitchell Shire — including Kilmore, Broadford, Seymour, Beveridge, Craigieburn, and Donnybrook.

Call us on 0431 193 102 or get a quote online.