Settlement is often caused by inadequate soil or base compaction. Other factors can be water in the base or soil, too thick a layer of bedding sand, or washed out bedding and joint sand. Loose or inadequate edge restraints will cause pavers to move apart. Pavers in uneven areas can be removed, the settlement adjusted, and the units reinstalled with no wasted paving materials or unsightly patches. If the base or soil has settled and is stable, remove the pavers and bedding sand, place and compact additional base material to the correct level, then add bedding sand. Bedding sand alone shouldn’t be applied to adjust the level of the surface if its thickness exceeds 1 1/2 in. (40 mm).
Concrete pavers can be removed for access to underground utilities, and reinstalled after repairs. When utility repairs are complete, fill the trench with base material and compact it. Remove about 18 in. (0.5 m) of pavers on either side of the opening, level the bedding sand and replenish as necessary. Re install the pavers, compact, fill the joints with sand and compact the surface again, filling joints as needed. ICPI Tech Spec 6-Reinstatement of Interlocking Concrete Pavements, provides step-by-step guidelines on removal and replacement of concrete pavers.