Safety Net Coverage Guide
1) Safety Net Coverage Planning Basics
Safety net coverage is planned as a continuous catch surface beneath elevated work, sized to protect people from falls and to intercept dropped tools. This calculator estimates required net area, panels, and tie points using conservative allowances. Typical planning inputs include work-zone dimensions, fall height, openings, and panel overlap.
2) Typical Coverage Geometry on Sites
Many installations can be modeled as a rectangle that surrounds the work zone. The net length and width are expanded by an overhang on all sides to account for swing, bounce, and positional uncertainty. The gross coverage area is then adjusted for edge sealing and any deducted openings within the footprint.
3) Overhang Selection from Fall Height
Overhang is a practical way to extend protection beyond the immediate edge. As a rule-of-thumb in planning, smaller fall heights often use about 2 m, moderate heights about 3 m, and higher falls about 4 m of overhang. Site rules, net rating, and access constraints may require a custom value.
4) Handling Openings and Penetrations
Openings such as shafts, atriums, or planned voids can be deducted when they do not require netting, but only when edge protection prevents lateral entry. If an opening is inside the coverage zone, consider separate netting or secondary controls. Document the opening area you deduct so procurement and inspection remain aligned.
5) Panel Selection and Overlap Impacts
Net panels are rarely installed edge-to-edge without overlap. Lacing, stitching, or connector hardware consumes effective coverage, so overlap is treated as a percentage reduction in usable panel area. Common planning overlaps range from 8% to 15% depending on attachment method and perimeter detailing.
6) Edge Gaps, Ties, and Anchorage Layout
Edge gaps can occur where nets meet structure, around columns, or near changing elevations. Applying a small gap allowance (often 2% to 5%) helps avoid under-sizing. Tie points are estimated from the net perimeter and your chosen spacing, such as 0.5 m to 0.8 m, to support an organized anchorage layout.
7) Allowances, Waste, and Procurement Checks
A safety factor adds coverage margin for measurement uncertainty, site changes, and installation tolerances. Procurement waste accounts for trimming, damaged mesh, and spare inventory. Many teams carry 3% to 10% waste and a 5% to 15% safety factor, then validate the final bill of materials against supplier panel availability.
8) Field Verification and Documentation
Before installation, verify actual spans, anchor locations, and obstruction clearances. Confirm that the net rating, connector method, and tie spacing meet project requirements and local regulations. After installation, record final dimensions, overlap method, and inspection notes so crews can maintain consistent coverage during shifts and phases.