Design 9m Galvanized Garden Trellis

I need a single 9-metre galvanized-steel trellis that will stretch across my garden and reliably carry vigorous climbing vines season after season. The span must resist rust, withstand wind loads typical for an open suburban backyard, and sit neatly between two existing concrete footings that are already 9 000 mm apart.

What I will supply:
• Exact footing positions and ground level survey once the project starts
• Photographs of the garden area for context

What I expect back:
• Scaled drawings (PDF + editable CAD) detailing posts, cross-members, and all fixings
• A concise materials list with section sizes, zinc-coating spec, and estimated quantities
• Step-by-step assembly/installation notes that a competent handyman can follow
• A brief maintenance guideline so the finish lasts at least 10 years with minimal care

I’m open to round, square, or RHS members as long as they remain slim enough to look elegant yet strong enough to support mature vines. Feel free to optimise the design for locally available steel sections to keep costs reasonable. If you have questions about site conditions, plant loads, or preferred connection methods, just ask so we get the details right the first time.