Before applying ARC, the surface should be damp to ensure the substrate does not absorb it and it only works on the surface. Always test on a small area before going ahead with the full application.
Syntec ARC – Acid Replacement Cleaner
ARC is an acid free cleaner that can be used (with caution) on renders, bricks, paving etc with areas of heavy algae or dirt contamination. Normally diluted 1:5 with fresh water, ARC should be handled in the same way as an acid based product. Do not use on Grey Sandstone Paving