Indian sandstone cleaning and the removal of the black spot that occurs on it.
Owners of Indian sandstone patio’s soon realise that they start to go green from the minute they are laid. This is due to the high porosity of the stone . After the green algae comes lichen…this usually forms as “black spot” . Any body who has tried to remove black spot from indian sandstone will testify it’s virtually impossible using conventional pressure washing methods.
We have devised a method for treating and removing this type of organic staining without damaging the substrate below or the pointing.
Today we were in Preston in Lancashire cleaning such a job . Please have a look at the before and after images of our work.