What happens if you leave it
Zebra-striped DIY washing
A consumer pressure washer leaves visible lap marks (the 'zebra stripe' effect) because hand-held lance speed is inconsistent. A rotary surface cleaner removes this entirely.
Slippery winter paving
Moss and algae on paving are an autumn/winter slip hazard. Insurers and visiting tradesmen notice. So do guests on the path to your front door.
Blown-out joints
The wrong pressure and angle blast jointing sand straight out of block paving — accelerating weed growth, settlement and unevenness.
Re-greening within months
Pressure-washing alone doesn't kill the biological cause. The black/green staining returns within a season. Pair with softwashing for a result that actually lasts.