Why natural stone is different
Sandstone and slate are softer and more porous than concrete. Full high pressure can strip the surface or force water into the stone. We soft-wash at lower pressure and use a biocide treatment to lift algae and lichen without damaging the material.
What's included
Soft wash at a pressure matched to the stone type, plus a biocide chemical treatment to slow regrowth of moss and algae.
Typical cost
A typical natural stone patio (30-50m²) runs £240-£400 depending on how established any moss or algae growth is.