Cleaning Concrete and Mono Block Driveways

Poured concrete and mono block paving get lumped together because both go grey and green in the same way, but they fail differently under a pressure washer. Concrete is a single slab, so the risk is the surface itself: too much pressure in one spot lifts the cement paste and exposes the aggregate underneath, leaving a permanently rougher, lighter patch that catches dirt faster than the concrete around it.

Mono block, sometimes called block paving, is dozens of separate units held in place by the sand between them. Wash that sand out and the blocks lose their interlock. They start to rock underfoot, edges chip where they knock together, and weeds get a clear run at the gaps. That is why a proper block job finishes with re-sanding, not just rinsing.

The patchy, striped finish people end up with almost always comes from a pinpoint lance held too close and swept unevenly. A rotary surface cleaner covers the whole width at a consistent distance, which is what gives you an even tone instead of a zebra pattern you can still see two summers later.

Both surfaces benefit from treating the growth rather than blasting it. Algae and lichen have roots into the pores; if you only remove what is visible, it is back within months. A soft wash kills it properly first, and the rinse then lifts dead growth rather than fighting living growth.

Sealing is optional on concrete and worth considering on block. On block it stabilises the joint sand as well as slowing staining, which is the main reason a sealed drive stays looking sorted for longer.