Slate Boss field tools
Slate exposure and quantity calculator.
Enter the actual slate size, required headlap and roof area to estimate nominal exposure, theoretical pieces per square and a planning quantity.
Field calculator
Slate exposure and quantity
Planning tool only. Results cover theoretical field slate. Starters, top courses, hips, valleys, rakes, penetrations, patterns, sorting, breakage and project specifications can materially change the order. Confirm headlap, pitch and quantity with the design professional, supplier and qualified slater.
| Slate size | Exposure | Field pieces / square | Field coverage / piece |
|---|---|---|---|
| 12×8 | 4.50 in. | 400.0 | 36.0 sq. in. |
| 14×7 | 5.50 in. | 374.0 | 38.5 sq. in. |
| 16×10 | 6.50 in. | 221.5 | 65.0 sq. in. |
| 18×12 | 7.50 in. | 160.0 | 90.0 sq. in. |
| 20×10 | 8.50 in. | 169.4 | 85.0 sq. in. |
| 22×11 | 9.50 in. | 137.8 | 104.5 sq. in. |
| 24×12 | 10.50 in. | 114.3 | 126.0 sq. in. |
| 24×14 | 10.50 in. | 98.0 | 147.0 sq. in. |
The table uses nominal dimensions and 3-inch headlap. It does not include waste or special courses. Actual slate dimensions and project requirements control.
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