Colour Range
Slate Ventilator


The following technical details have been calculated in accordance with BS 5534: Part 1: 1997 Slating and Tiling and BS 8000: Part 6: 1990 Workmanship on building sites. It has been pointed out that these are minimum recommendations. Conditions on individual sites vary, advice should be sought if there is doubt that the details below are not suitable.

It is recommended that slate crates are placed on level ground and stacked no more than two crates high on building sites.

Slates are preholed at the quarry in order to reduce the wastage factor.

In general building practice it is normal to allow up to 5% wastage when estimating quantities.

User Guidance Notes
Grade slates into three or four groups of equal thickness.

Timber Batten size 50mm x 25mm for double lap slates. Recommended for 450mm and 600mm span.
Battens fully supported by boarding, sheathing and sarking can be reduced to a minimum size of 38mm x 19mm.

Batten gauge
= length of slate – lap size divided by 2

Holing gauge
= Batten gauge + head lap +8 to 15mm.

Eaves slate length
= Batten gauge + head lap.

Verge slates should not be less than 150mm wide.
Nails should comply with BS 1202: Part 2 Copper clout minimum shank diameter 3.35mm. The type of
shank on the nail will depend on site exposure.

For details on severe exposure click below

For details on moderate exposure click below

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