| Size of slate |
600mm x 300mm |
500mm x 250mm* |
| Minimum pitch**: Moderate exposure |
22.5° (100mm lap) 20° (110mm lap) |
22.5° (100mm lap) |
| Minimum pitch**: Severe exposure |
25° (100mm lap) 22.5° (110mm lap) |
25° (100mm lap) |
| Maximum pitch |
90° |
90° |
| Typical laps |
100, 110mm |
100mm |
| Slate hooks |
Hook fixed 100 -150mm |
Hook fixed 100mm |
| Maximum gauge |
245 – 250mm |
200mm |
| Slate thickness |
4mm |
4mm |
| Covering capacity (net) |
13.4 slates/m2 at 100mm lap 13.6 slates/m2 at 110mm lap 14.8 slates/m2 at 150mm lap |
20.0 slates/m2 at 100mm lap |
| Weight of slating (approx) |
20.4 kg/m2 (0.20 kN/m2) at 100mm lap 20.9 kg/m2 (0.20 kN/m2) at 110mm lap 22.8 kg/m² (0.20kN/m2) at 150mm lap |
21.3 kg/m2 (0.21 kN/m2) at 100mm lap |
| Battens required (net) |
4.00 lin.m/m2 at 100mm lap 4.08 lin.m/m2 at 110mm lap 4.45 lin.m/m2 at 150mm lap |
5.00 lin.m/m2 at 100mm lap |
| Batten size recommended (fixed to BS 5534) |
50 x 25mm for rafters/supports not exceeding 600mm centres
|
50 x 25mm for rafters/supports not exceeding 600mm centres
|
| Fixings |
Slate nails (30 x 2.65mm) Copper disc rivets (19mm dia. x 2mm stem) |
Slate nails (30 x 2.65mm) Copper disc rivets (19mm dia. x 2mm stem) |
| Fitting Screws |
14 gauge self sealing
|
14 gauge self sealing
|
| Slate hooks*** |
Length to equal to lap |
Length to equal to lap |
| Authority |
BS EN 492 |
