Create a sustainable drainage system and direct surface water with ease using Bradstone's Permeable Jointing Aggregate (25Kg)! This highly efficient aggregate is made up of tiny pieces of crushed stone that are perfect for filling the joints between permeable block paving. Not ...Create a sustainable drainage system and direct surface water with ease using Bradstone's Permeable Jointing Aggregate (25Kg)! This highly efficient aggregate is made up of tiny pieces of crushed stone that are perfect for filling the joints between permeable block paving. Not only will it help achieve recommended attenuation levels, but when used in conjunction with our 6mm permeable paving aggregate you can construct an entire pervious patio or walkway!