Q.: The concrete subcontractor who placed some sidewalks for us didn't cut any joints, so there are meandering cracks in the sidewalk. Does any company make expansion-joint covers for this application?
A.: Expansion-joint covers won't be of much use unless the cracks are nearly straight. The covers will also look odd since the cracks probably aren't equally spaced as joints would be. Most repair attempts will make the cracks more obvious, so our advice is to do nothing. If the subgrade or base is adequately compacted, faulting may not occur. If the slabs do fault at the cracks, the edges should be ground so they don't create a tripping hazard.
As an alternative, you could epoxy-inject the existing cracks, saw joints at a spacing equal to the sidewalk width, and apply a polymer-modified cementitious microtopping.