Heavy Duty Paving otherwise referred to as ‘ex council slabs’ comes in one uniformed size 600 x 600 and is 50mm thick. This paving is hard wearing and has strong durability for utility areas rather than feature patios.. It comes in one colour, grey. These are the only paving slabs we would recommend to use for driveways, but they would still require a good base beneath them. As well as driveways, they are commonly used for shed bases. Colour may vary from batch to batch. We recommend sticking with the same batch number when ordering slabs. Occasionally dark or light patches may occur on the surface of the slab.