The joints in my stone courtyard have gone dark. Does it need relaying?

In stone pavingStone pavingA floor of natural stone slabs, irregular or cut, in courtyards, walkways, terraces and on steps. The stones are bedded in mortar and the joints between them are filled. the stones last for years, but the joints between them don't last as long. They darken with dirt and damp, wear down under foot traffic and crumble in places. The courtyard then looks dark and tired, and water gets in and weeds grow through the open joints.

In this restaurant courtyard the old joints had darkened so much they barely stood out from the stone. They were filled again with white material, stone by stone, and the same was done along the entrance walkway. The stones stayed where they were, and their pattern showed again, day and night.

In general, wherever the old joint is crumbling, it has to be cleaned out first so the new material can bond. But if some stones rock, have crackedCrackA split or gap in render, concrete, a wall, a coating or wood. Fine cracks are usually only on the surface; ones that grow, keep reopening or run diagonally need attention. or have sunk, new joints aren't enough: those stones need relaying first.

The colour of the joint makes a big difference. A light joint makes the pattern of the stone stand out, while a dark one shows dirt less. It's worth deciding before the work starts.