Blue / Black Roof Slate / Special offer roof tiles / By stoneandslate Size (mm) Price (£) (excluding VAT and delivery) per sq.metre (m2) coverage per tile 300 x 200 17.76 0.40 400 x 200 17.86 0.58 400 x 250 18.70 0.75 500 x 250 19.74 1.05 Non fading, pre-holed.