What would cause areas of a beautiful dry-laid paver project to caved in or sink? We’ll give you the answer in a second. But we can’t tell you the number of homes we have seen where this occurred on the porch stoop and/or walks. Some of these porch floors had areas where the pavers were so caved in that the floor was literally falling apart.
Paver Porch Stoop & Paver Walk Failure
Dry laid paver projects are very popular with homeowners, as a way to add value, beauty, architectural detailing, and enjoyment to a home. Pavers can be manufactured from concrete, or made of clay. In a dry laid application, the pavers are not mortared, but installed with sand joints and a bedding of sand underneath.
Pavers are only the decorative finish of a hard surface; they are not the structural part of the surface, just as the hardwood flooring in your house is not the structural part of the floor.
The cause for the failure of those paver projects is what is below the pavers – and that is a sub-standard base, the absence of a base, and/or a poorly prepared subgrade (ground) below the base. Any or all of these conditions will result in structural failure of the pavement. For more information, read our article on aggregate base for pavements.
If your contractor wants to install the pavers, for example, just using a bed of sand right on top of the ground, or perhaps tells you that the project only requires a couple inches of loose gravel for a base, a warning flag should go up, and it would benefit you to find another contractor.
A dry laid paver project installed by a professional contractor should include:
- properly preparing the subgrade – tamping and firming the ground, and filling in any low spots or voids
- aggregate base – a crushed aggregate mix of stone ranging in size from 1” to tiny granular fines; the correct depth of base will depend on the load-weight the paver surface will have to carry; aggregate bases for driveways are greater in depth than bases for a walk or patio
- paver restraint edging (used for walks, driveways, patios) – What is paver restraint edging?
- sand bedding – usually 1 ½” deep
- pavers – after the pavers are installed, sand is swept across them to fill the joints
We can only guess that many homeowners may not know how a paver project should be constructed, and as a result they may be paying for inferior workmanship.