Choosing the right wire diameter
Wire diameter typically ranges 2mm to 3mm. Thinner 2mm cable is common for lower-floor balconies and windows with modest spans. Thicker 2.5-3mm cable is generally specified for higher floors, longer spans, or areas with more wind exposure, since greater diameter adds tensile strength for the additional load these conditions place on the system.
Choosing cable spacing
Spacing typically ranges 2 to 4 inches. Wider 3-4 inch spacing is common for adult-only fall safety where children or pets aren't a concern. The tighter 2-inch spacing is the recommended standard for households with young children or small pets, since it meaningfully reduces the gap a small body could squeeze through.
How diameter and spacing work together
These two specs aren't independent — a longer span with wider spacing places more load per cable during a stress event than a shorter span with tighter spacing, so your installer should be considering both together based on your specific opening, not applying one fixed combination everywhere.
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Frequently asked questions
What diameter is typical for a standard balcony?+
2mm to 2.5mm for most standard balconies; higher floors or longer spans may use up to 3mm.
What spacing should I choose if I don't have children or pets?+
3-4 inch spacing is common for adult-only fall safety, though many households choose 2-inch anyway since it doesn't meaningfully affect the view.