Colorbond fencing is one of the most popular boundary fence choices in Melbourne — but installing it on a slope adds a layer of complexity that catches many DIYers off guard. The good news is there are two well-established methods, and once you understand the difference, the right choice for your block becomes obvious.

Raked vs Stepped: The Two Methods

Raked (Angled) Fencing

In a raked installation, the fence panels follow the angle of the slope continuously. The top and bottom rails are set at an angle, and the fence sheets are cut to match the slope.

Best for:

• Gradual, consistent slopes
• Properties where you want to minimise gaps at the base of the fence
• Situations where the fence line runs parallel to the slope

Challenges:

• Requires cutting fence sheets at an angle — more labour and waste
• Rails need to be custom-set at the correct angle
• Not suitable for very steep slopes where the angle becomes impractical

Stepped Fencing

In a stepped installation, the fence is built in flat sections that "step" down the slope. Each panel is level, and the height difference between panels creates a step at each post.

Best for:

• Steeper slopes
• Situations where a level fence line is preferred for appearance
• Easier DIY installation — no angled cuts required

Challenges:

• Creates triangular gaps at the base of each step
• These gaps may need to be filled with a concrete plinth or infill panel
• Can look less polished on very gradual slopes where the steps are small

Which Method Should You Choose?

As a general guide:

• Slope under 5 degrees: Either method works; raked looks more seamless
• Slope 5–15 degrees: Stepped is usually easier and looks cleaner
• Slope over 15 degrees: Stepped is the practical choice; raked becomes very difficult

If you're unsure, bring a photo of your fence line to FPM and we can advise on the best approach.

Step-by-Step: Installing a Stepped Colorbond Fence on a Slope

Step 1: Mark Out Your Post Positions

Standard post spacing for Colorbond fencing is 2.4 metres between posts. On a slope, keep this spacing consistent — don't be tempted to stretch it to reduce the number of steps.

Use a string line and stakes to mark your post positions along the fence line. On a slope, you'll need to decide the height of each step — typically 75mm to 150mm per panel is manageable.

Step 2: Set Your Posts

Colorbond fencing uses either C-channel posts or square posts, set in concrete footings.

• Dig post holes to a minimum depth of 600mm (deeper on soft or sandy soils)
• For a 1.8m fence, use 2.4m posts — the extra length goes into the ground
• Set each post plumb (perfectly vertical) using a spirit level
• Pour rapid-set concrete around each post and allow to cure for at least 24 hours before attaching rails

On a slope, each post will sit at a different height above ground. This is correct — the step is created by the difference in rail height between adjacent posts.

Step 3: Attach Your Rails

Colorbond fencing uses top, mid, and bottom rails (for 1.8m panels). On a stepped fence:

• Set the rails level on each individual panel
• The step occurs at the post — one panel's rails will be higher than the next
• Use a spirit level on each rail to confirm it's horizontal before fixing

Step 4: Slide in the Fence Sheets

Colorbond fence sheets slide into the C-channel of the rails. On a stepped fence, each sheet is a standard size — no cutting required. This is one of the main advantages of the stepped method.

• Start from one end and work along the fence line
• Ensure each sheet is plumb before moving to the next
• Fix sheets to rails with tek screws at the top and bottom

Step 5: Handle the Gaps

The triangular gaps at the base of each step are the main aesthetic challenge of stepped fencing. Options include:

• Concrete plinths: FPM stocks plain concrete plinths that can be cut to fill the gap — this is the most durable and tidy solution
• Infill panels: Small custom-cut Colorbond panels can be fitted into the gap
• Timber infill: A treated pine or hardwood infill can work in informal settings

For most Melbourne properties, a concrete plinth is the cleanest solution and adds a finished look to the base of the fence.

Materials You'll Need

For a standard stepped Colorbond fence on a slope, you'll need:

• Colorbond fence sheets — 1.8m x 2.4m panels in your chosen colour
• C-channel posts — 2.4m length for a 1.8m fence
• Top, mid, and bottom rails — in matching Colorbond colour
• Post caps — to finish the top of each post
• Rapid-set concrete — for post footings
• Concrete plinths — to fill step gaps (optional but recommended)
• Tek screws — for fixing sheets to rails

FPM Building Supplies stocks the full Colorbond fencing range including posts, rails, sheets, and caps in all standard Colorbond colours. Visit us at 32 Fullarton Dr, Epping VIC 3076 or call +61 431 235 919.

Do You Need a Permit?

In Victoria, boundary fences up to 2 metres high generally don't require a building permit. However, if your fence is on a slope and the height varies significantly along its length, check with your local council. The fence height is measured from the natural ground level at each point, not from the lowest point of the slope.