Forticrete Concrete Plain Tile & Half - Slate Grey Please note that deliveries to Scotland for this product will incur additional delivery charges. Please note this is the tile & half for the concrete plain tile in slate grey. Tile & half are laid at the start and finish of every other course. Dimensions Length: 268mm. Width: 248mm. Fixings Plain Tiles are laid broken bond in courses with not more than 65mm headlap for roofing and not less than 35mm for vertical tiling. Tiles are fixed with three 38mm x 3.35mm aluminium nails in at least every fifth course for roofing and every course for vertical tiling. Nail holes are located approximately 35 mm down from the head of the tile and approximately 40mm in from the side edges.