Page 11 – Materials and components required
Standard specification and details
Material and Components Required for Roof Slating
When selecting materials and components for roofing particular note should be taken of BS5534:2014 (Slating and tiling for pitched roofs and vertical cladding) and BS8000-6:2013 (Workmanship on building site – Part6: Code of practice for slating and tiling of roofs and walls). You should always, where practicable, adhere fully to the standards set out therein.
Ensure that any slates you choose to use fully comply with BS EN 12326-1. Slates need to be of the correct size for the roof pitch. Stick to larger size slates for shallow pitches and smaller sized slates for steeper pitches.
Slate nails should be either Stainless Steel, Aluminium or Copper. We always use Copper nails with natural slates. Galvanised nails are not acceptable as the protective coating can easily be scratched by the slate and cause rust over time. Nails should be 20mm to 25mm longer than two thicknesses of slate. A longer nail is required for the eaves course, particularly if a sprocket is used. Nails should be in either cut or wired finish and have a head size of at least 10mm diameter. The shaft should be at least 3.0mm thick. Some manufacturers may ask for even thicker nails to be used and these guidelines should be followed.
Roofing battens must comply with BS5524:2014. Batten length should be sufficient to span over a minimum of three supports/rafters. Battens used for natural slating must not be less than 50mm x 25mm in size. Battens should be factory graded.
Batten nails should be made of zinc-coated in accordance with BS EN 10230-1. They should be at least 30mm longer than the thickness of the battens and a gauge of at least 3.0mm if used with an underlay or 3.35mm if used without. Longer nails should be used in areas of increased exposure.
The roofing underlay should be of suitable strength, water resistance and durability for the proposed application. This can be either a reinforced bitumen underlay of type 1F or 5U, or a vapour permeable underlay of type LR.
Ridge tiles should be angular, segmental or half-round. These may be bedded with mortar or laid with a dryfix system. All ridge tiles must be mechanically fixed – dryfix systems are mechanically fixed by design but with a bedded system you must use additional mechanical fixings. This usually means drilling and nailing/screwing your ridge tiles to your ridge batten.
Hips irons should be formed from metal strip, preferably wrought iron, 25mm wide, turned up at the end by an amount sufficient to support the hip covering. It must be galvanised after manufacture. Roofs with pitches more than 50° should be formed in 6mm metal strip, and below 50° in 3mm metal strip.
Lead roll is highly suitable for use at ridges and hips as an alternative covering to ridge tiles. Lead soakers are commonly used at abutments and mitred hips and valleys (code 3) and lead flashings (code 4) at abutments. Minimum thicknesses of lead for each application can be found in BS5534:2014. Information and standard details should also be attained from the Lead Sheet Association. On completion of roofing all exposed lead surfaces should be coated with patination oil or cream to avoid unsightly staining of the slates.