Size of slate |
600mm x 300mm |
Minimum pitch**: Moderate exposure |
22.5° (100mm lap) 20° (110mm lap) |
Minimum pitch**: Severe exposure |
25° (100mm lap) 22.5° (110mm lap) |
Maximum pitch |
90° |
Typical laps |
100, 110mm |
Slate hooks |
Hook fixed 100 -150mm |
Maximum gauge |
245 – 250mm |
Slate thickness |
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 |
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 |
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 |
Batten size recommended (fixed to BS 5534) |
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) |
Fitting Screws |
14 gauge self sealing
|
Slate hooks*** |
Length to equal to lap |
Authority |
BS EN 492 |