Metal System Spec & Cost Estimator

Exposed fastener panels (R-panels) typically have a 5–7% waste factor because they can be easily lapped and reused. Standing seam requires a 10–12% waste factor due to the non-reversible nature of the proprietary locking systems and precision flashing requirements.

Rule of thumb is to order 1.1x the total perimeter for drip edge and rake trim. For valleys and ridges, use a 1.15 multiplier to account for miter cuts and overlaps at junctions, which are the most common source of metal-roof 'shortages'.

For standard AG/R-panels, use 80 fasteners per 100 sq. ft. For high-wind zones, increase to 120 fasteners per square. Fasteners should be ordered in bulk bags (typically 250 count) to protect against job-site loss and ensuring a uniform seal.