A 24×30 ft gable roof at 4/12 with 12-in overhangs needs 22 panels of 36-in coverage (11 per side), each 13' 9" long, plus about 702 screws.
| Item | Length | Buy |
|---|---|---|
| Ridge cap | 32 ft | 4 × 10½ ft |
| Eave trim | 64 ft | 7 × 10½ ft |
| Rake trim | 55 ft | 6 × 10½ ft |
| Inside closures (eave) | 64 ft | 22 × 36 in |
| Outside closures (ridge) | 64 ft | 22 × 36 in |
| Profile | Panels | Lin ft | Panel cost |
|---|---|---|---|
| 36-in rib panel36-in coverage | 22 | 303 | $1,232 |
| 5V crimp24-in coverage | 32 | 440 | $1,504 |
29 ga Galvalume prices from McCoy's (San Marcos, TX), Oct 23, 2026; cut-to-length uses the same per-foot rate. Eave and rake trim vary by supplier — get a quote with the panels.
| Pitch | Panel length | Panels | Roof sq ft | Screws | Panel cost |
|---|---|---|---|---|---|
| 3/12 | 13' 5" | 22 | 858 | 687 | $1,232 |
| 4/12 | 13' 9" | 22 | 877 | 702 | $1,232 |
| 5/12 | 14' 1" | 22 | 901 | 722 | $1,342 |
| 6/12 | 14' 7" | 22 | 930 | 745 | $1,342 |
| 8/12 | 15' 8" | 22 | 1,000 | 800 | $1,342 |
Roof area: 32 × 26 ft of plan × 1.054 = 877 sq ft (8.8 squares). At Fabral's 80 screws per square that's 702 panel screws — #14 × 1 in Woodtite into a plywood or OSB deck, #10 × 1½ in into purlins — before trim and stitch screws.
Under 3/12 the IRC requires lap sealant on exposed-fastener panels; 36-in rib panels are rated down to 2½/12 by their makers and 5V crimp to 3/12. At 4/12 either profile is fine without sealant.
The full method, material data and tips are on the main metal roofing calculator page.