Description Redland's Westminster Slate is a large format, single lap interlocking flat clay tile with variable gauge with a full range of complementary fittings and accessories.   Westminster Slate is a coste effective high-performance roof covering. With a tapered leading edge providing an exceptionally thin appearance and a hidden interlock, Westminster Slate is an elegant clay tile, engineered to perform at pitches as low as 17.5.    With a coverage of less than 10 tiles/m, it is simple and quick to install offering savings in both materials and labour. Available in 3 classic colour choices: (79) City Black, (80) Cardinal Red and (82) Old College Red. Colour City Black's colour is achieved by the application of black engobe over the top surface and ends of the tile. Engobe is a ceramic material applied prior to firing. The high clay content of the engobe ensures that when the tile is fired, the tile and engobe fuse together becoming one, such that the engobe will last as long as the tile itself.   The black tiles also have manganese added to the clay to darken the body. This ensures a dark appearance is maintained if the tiles are cut.When using City Black Slates, use either Black Clay Universal Angle Ridge Tiles to match the slates or Red Clay Universal Angle Ridge Tiles where a contrast to the slates is desired.   Technical Size (overall): 480 x 326mm Minimum pitch: 17.5 The minimum pitch is based on a maximum rafter length of 10 metres. Maximum pitch (subject to fixing specification): 90 Minimum headlap: 110mm Maximum headlap: 140mm Minimum gauge/batten spacing: 340mm Maximum gauge/batten spacing: 370mm Hanging length (approx): 452 mm Linear cover of one slate: 280 mm Covering capacity (at max gauge): 9.7 tiles/m Covering capacity (at min gauge): 10.5 tiles/m Weight (at max gauge): 47.5 kg/m Weight (at min gauge): 51.5 kg/m Battens required (at max gauge): 2.7 m/m Battens required (at min gauge): 2.9 m/m