From: Laboratory tests to understand tephra sliding behaviour on roofs
Roofing material | Cell over ridge or trough | Mean empty cell sliding angle (°) | Mean sliding angle (°) with 10 cm thickness of pumice |
---|---|---|---|
Fibre cement | Ridge | 24 | 32 |
Fibre cement | Trough | 21 | 32 |
Metal sheet | Ridge | 19 | 26 |
Metal sheet | Trough | 13 | 27 |
Tile (no PTFE tape) | N/A | 32 | |
Tile (with PTFE tape) | N/A | 24 |