Kiln-dried sand is dry, fine sand with no moisture content. It is used for filling block paving and paving slab joints. This type of sand stops water ingress and pavements from getting loose. For this type of sand to work as it should, water must completely be removed from it. Know more, https://completedrivesandpatiosltd.co.uk/blog/kiln-dried-sand-for-block-paving/