Stonecare4U's Block Paving Cleaner is a high-performance outdoor cleaner formulated to perform against typical grime, dirt and stains on block paved surfaces. Within just 2 hours, and without scrubbing, it will eliminate layers of grime, dirt and lichen from your pavers. This cleaner also contains a biocide that helps to eliminate organic matter between pavers, such as weeds, green growth, leaf mulch etc. For spotless results, we recommend you allow the cleaner to dwell for about 2 hours (lightly re-applying water if the surface starts to dry) and then once the cleaners have worked into the stone’s top layers, do some brushing and/or a pressure spray to really dislodge the embedded dirt, grime and stains for an immaculate finish.