Our ready-to-use path and patio cleaner will clean up to 85 square metres. This surface biocide is for amateur use against algae, mould and lichen. This non-acid-based exterior hard surface cleaner can be used on a wide range of hard surfaces such as brick, tarmac, asphalt, block paving, concrete and stone. Unlike acid-based treatments, this formula uses chemicals to clean instead of corroding away the surface. It's specially formulated to remove a wide range of stains from exterior surfaces such as paths, driveways, patios and walls. Always read full packaging and directions before use. Size: 2L. Directions for use: Wearing protective gloves measure out the required amount as per the table below and add to water in a low-pressure garden sprayer, watering can, trigger spray, lance sprayer, or battery-operated sprayer, and mix for 20-40 seconds.