NewUrbanStreets

If you have read a few of my posts about paver surfaces you have read about the importance of sand in the joints. As I walked from a meeting back to the office the other day I was reminded of a situation that should/could be avoided that can accelerate the migration of the sand.

The problem is when small slices or pieces of pavers are needed to fill a very narrow gap that is too wide to be only sand. So, the gap is filled with a 1-inch or less “slice” of paver that is floating on top of the sand bed and between the concrete edge of the recess and the next paver. To make matters worse the sliver is the last piece to place and must be tapped into place carefully to not break it.  It is not trapped between two pavers but instead rests between the adjacent paver and the concrete edge. The small piece can become loose more quickly and the sand migrates out causing the paver structure to begin unraveling.

How can that situation be avoided? The answer is twofold. First the design of the recess should require an overall space that fits the dimensions of the paver courses so there are only pavers cut in half in the worse case. Second, the construction documents should include bold notes on the details and plan view of the recess that the dimensions are critical and care must be taken to have the forms correct before the concrete is poured. Tell your inspector to nag the contractor about the care needed to avoid extra costs for him.

If the completed recess is still not built to suit the dimensions of the paver coursing then the contractor can be required to jack-hammer it out and start over. Or, saw cut the recess larger to “fit” the paver coursing. Once the new edge is cut they will have to chip out the concrete and bush hammer (a special bit on a jack hammer) the bottom surface to make it relatively flat so the 1-inch thick sand bed is about one inch thick. Also make them grind a small amount off the remaining saw-cut edge so there is not a sharp corner to flake away randomly.

Avoiding small pieces of pavers is a good thing even in sidewalks. But since you do not have the loads and water conditions you will not see the degree of problems. But, with sidewalks the cosmetic factor is more important and the small slices look like someone did not plan ahead.