Keep in mind that the thickness of the lift affects compaction. Anything above 8-inch lifts will be more difficult to effectively compact, while the over compaction of lifts under 4-inches can lead to decreased densities due to material segregation, fracturing or pushing.

In addition to lift thickness, compaction is also affected by moisture content. Adding moisture with a garden hose or a compactor's on-board water tank allows the sub-base particles to create a paste and bond together forming a much stronger finished product. However, it is important to not saturate the sub-base material. To test moisture, pick-up a handful of sub-base and squeeze it. Properly moistened material will hold together in a solid clump.

Following the addition and proper compaction of the sub-base layer, a one-inch layer of sand bedding is placed over the entire surface area to connect the pavers to the sub-base and allow a softer surface into which the pavers can settle.

After the pavers are placed in the desired pattern, the surface should be compacted. Two to three passes are usually recommended to press the pavers into the sub-base. Once again, check manufacturer literature for specific recommendations. Because the pavers used for most North American landscaping projects are synthetically produced and not as strong as the granite stones used in Europe, a protective mat should be attached to the bottom of the compactor in the final stages of compaction. Most manufacturers offer a protective mat option for compactors.

Once the initial compaction of the pavers has occurred an additional two to three passes should be made over the pavers as fine sand is swept into the joints. This final compaction will settle the pavers into the sand and create density between the pavers. Once again, a protective mat should be placed on the compactor to prevent damage to the surface of the pavers.