Choose 300mm for a shallow decorative finish, 450mm when you want a more noticeable topper without adding too much height, or 600mm when the trellis needs to contribute more significantly to screening as well as decoration.
The best height depends on whether the fence topper trellis is mainly a decorative finishing detail or needs to provide a more noticeable area of open screening.
300mm trellis is the shallowest option across our main topper styles. It works well where the aim is to break up the solid top line of a fence and add a relatively modest amount of extra height without making the trellis a dominant part of the boundary.
450mm trellis provides a middle ground. It adds 150mm more height than the 300mm version and creates a more noticeable band above the fence, while remaining considerably shallower than a 600mm panel. Our product guidance positions this size between a narrow decorative topper and a deeper screening section.
600mm trellis has enough depth for the trellis pattern to become a much more significant part of the finished fence. In our privacy square and horizontal slatted ranges, this is where the panel starts to provide more meaningful filtered screening as well as decoration, although it remains an open structure rather than a solid privacy panel.
The pattern matters as well as the height. Traditional square trellis has approximately 100mm openings, while privacy square trellis uses closer openings of approximately 50mm. A 600mm privacy topper will therefore screen more closely than a 600mm traditional topper even though both add the same amount of height.
Whichever size you choose, add the topper height to the existing fence height when planning the finished boundary.