Stonecare4U Driveway Cleaner is a high-performance cleaner for cleaning all types of external natural stone driveways. It is also suitable for all outdoor stone & masonry surfaces. Apply and leave for 2 hours, it works also works on algae, lichen and black spots, removing recent and aged dirt and grime! The alkaline-based solution won’t damage or etch the surface like other cleaners. This cleaner also contains a biocide that helps to eliminate organic matter between slabs/blocks, such as weeds, moss, leaf mulch etc. For spotless results, we recommend you allow the cleaner to dwell for about 2-4 hours, lightly re-applying water if the surface starts to dry. Once the cleaner has worked into the stone’s top layers, brush vigorously and/or pressure wash to really dislodge the embedded dirt, grime and stains for an immaculate finish. Please Note: Stonecare4U Driveway Cleaner contains a chlorine type agent as an active ingredient and will stain fabrics and sensitive materials. Take special care to avoid contact with fabrics & tarmac during application. The fluid might cause slight lightening of some surfaces – always try the product in an inconspicuous area prior to use.