Tegral Eternit Diamond slates are integrally coloured fully compressed fibre-reinforced cement slates, manufactured from Portland cement, synthetic fibres, pigments and additives, using the Hatscheck process. Slates are punched, pressed, heat cured and stored.
Size: Length/Width ±3mm
Thickness: 4mm nominal -0.4/+1.0mm
3 fixing holes: ±2.5mm in any direction.
In common with all building materials, Tegral diamond colours are subject to the natural influence of weathering, particularly associated with all roofing materials. The visual changes will vary depending on site location, aspect, roof pitch and local exposure conditions
30 years structural, 20 years colour
Storage on Site:
Tegral diamond slates should be stored indoors on a flat surface and not be allowed to become wet in storage. If outside storage is unavoidable, slates should be kept clear of the ground, the polythene slit and the stack covered with a tarpaulin, permitting air to circulate between the stacks.
Smooth, matt coating on face, protective seal on underside, edges straight, preholed.
Building Regulations ‘0’ classification. Unrestricted usage on roofs/walls.
Minimum roof pitch
No. of slate per m²
Linear m of battens per m²
Weight per m² as laid
Serious regard must always be had to local exposure conditions, with a steep pitch the better option in all situations. Reference to general slating advice contained in ICP2:2002 Code of Practice for Slating and Tiling is strongly advised.
Under normal circumstances, a minimum pitch of 35° is recommended with a 100mm head/side lap. For particular applications, especially in areas of severe exposure and long roof slopes, contact Tegral’s Technical Services Department for advice.
The roof space should be vented in accordance with the Building Regulations or other approved measures taken to control harmful condensation in roof voids.
The minimum requirement is Type 1F Roofing Felt to BS747 with minimum 150mm horizontal laps and 100mm vertical laps.
Timber battens – 50x22mm for 400mm span, 50x 35mm for 600mm span, at 190mm centres.
Ridge and Hip Cappings:
Colour-matching accessories are suitable for mono and duo roof situations and should be fixed to the top slating battens with brass or stainless steel screws with washers and caps.
Flashings & Soakers:
Lead or copper sheet fixed in accordance with LDA or CDA recommendations.
Slates and associated materials should be fixed having due regard to ICP2:2002, Code of Practice slating and tiling of roofs.
Health & Safety
Foot traffic on slate roofs should always be avoided. The relevant clauses of the Health & Safety Regulations for access to and working on slate roofs, should be carefully noted.
Tegral diamond slates are fixed with 2no. 30mm long copper slate nails to IS105, and a copper disc rivet. They should never be nailed too tightly with a 4mm gap left between the short vertical sides of adjoining slates. Slates can be cut with a scribe cutter and holes drilled with a standard drill bit. Remove all swarf prior to fixing.
Starting to Slate
Cut and fix a first under-eaves course and then do the same with a second course. Fix a third full size course over the two undereaves courses. Continue across and up the roof with whole slates, trimming to verges, hips, valleys and ridges as necessary.
Manufactured under ISO 9001 Quality Management System, and in accordance with the European Norm EN492:2012, Fibre cement slates and fittings.