Hero paving and decking power cleaner 25 litre is a quick and easy way to clean any outdoor hard surface no scrubbing involved simply mix apply and leave to dry the active ingredients break down garden grime such as algae moss and mould in around 1 3 days and goes on to protect against re growth for up to 9 months suitable for use on patios driveways decking block paving tarmac fencing roofing garden furniture upvc and brick children and pets need not be excluded from treated are