Interlocking pavers remain durable and new looking even after years of abuse and weather precisely due to the ‘interlocking action’ of the paving stones. Interlocking concrete pavers are designed specifically to leave gaps in between each brick – in other words, they do not sit exactly flush to each other. It is this space, paradoxically, that gives the entire structure its strength as soon as these joints are filled with an appopriate joint material, such as sand. The pavers are laid in a particular pattern (the pattern really is just how the joints are arranged), leaving a bit of space in between each and every paver. Mortar is not used to bind these joints together, as this would destroy the benefits of the sand-interlocked paver.