Gravel & Stone Cleaner & Restorer

Patio and driveway cleaners remove algae, mould, lichen and black spot, along with dirt, grime and building stains, from paving, paths and drives. The category also includes path and patio weedkillers, patio brushes and pressure washer patio cleaning attachments.

Types of cleaner

• Ready-to-use: pre-mixed, often in a trigger or pump sprayer, suited to smaller areas and problem spots.
• Concentrates: diluted with water before use, for larger areas.
• Algae and black spot removers: some are sprayed onto dry paving and left to work with the weather, with no scrubbing or rinsing. Green growth fades first; lichen and black spot take longer.
• Acid brick and patio cleaners: hydrochloric acid based, for cement and mortar stains and limescale. Do not use them on natural limestone, sandstone, marble or terrazzo, and test a small hidden area first, checking it again after 24 hours. Wet the paving first and rinse the cleaner off with plenty of water before it dries. Coloured concrete may lose some colour.

Weedkillers and equipment

Path and patio weedkillers are pesticides: use only products authorised for amateur use, and read the label before you choose one and again before use. Brush paving regularly with a stiff yard brush. If you pressure wash, hold the nozzle around 30 to 50 cm from the surface and move slowly and steadily, but never use a pressure washer to rinse off an acid cleaner.

Safety and run-off

Follow the manufacturer's instructions and safety data, and wear the gloves and eye protection they list. Keep children and pets away until the treated area is dry. Never pour weedkiller down a drain, sink or toilet, and keep cleaner run-off away from ponds, ditches, waterways, lawns and plants.

For weeds in borders and lawns, see weed control.