Professional installers often include a deep layer of crushed gravel under permeable pavers to allow more runoff to soak through into the soil below. Many installations will include multiple layers of gravel, with coarser aggregate at the base and finer aggregate that sits on top of that bottom layer. Above the gravel, you’ll often find coarse sand that helps reduce paver shifting over time. Some permeable paver designs include a water collection system set into the gravel layer to route runoff to a safe area for disposal.

The stones do not work well on uneven ground. If the stones are not buried into the ground and made level upon installation, they almost certainly will shift or crack on uneven ground. Additionally, rainwater or water from sprinklers can run under the edge of an uneven paver, causing erosion. In a freeze and thaw cycle, trapped water under the paver can cause the problem to worsen by shifting the stepping stones around. Use a bubble level to make sure the ground under each paver is as even as possible, even if the nearby ground is uneven.

While it may be less expensive initially to lay concrete vs. pavers, the long-term expenses that come with repairing concrete may prove to be less cost-friendly than simply replacing a few damaged pavers. On top of that, stamped concrete may only last for 25 years compared to pavers, which can last over 50 years.

Yes, but it's best to kill off the grass with solarization and remove the dead plant matter before laying down the pavers. This helps limit the chance of your pavers shifting as the dead plant matter decomposes.