The Industry Standard Joint System Saw cut joints filled with semi-rigid epoxy best meet requirements for joint performance. The saw cut is narrow. The epoxy has a relatively low strength and a Shore D and A hardness of about 50 and 80, respectively. This system performs better than any other any other joint system on the market. But the best isn't perfect.
Problems can still occur.
Saw cuts can be made too early or too late. Cutting too early causes raveling at the joint edges, an invitation to later trouble. Floors cut too late may crack at an unplanned location. Or a crack may form in front of the saw cut, creating an irregular joint opening that can't be filled properly. If the saw cut isn't deep enough to induce the crack, the crack forms somewhere else and shifts maintenance worries to that location.