Henley-on-Thames Sandstone Patio Restoration

This modern property featured a large cut sandstone patio that was heavily affected by black spot, along with extensive black and white lichen growth. Before any work began, we assessed the condition of the stone and planned the most effective restoration process.

Black spot and lichens are among the most stubborn forms of biological contamination found on natural stone. Sandstone’s porous surface allows these organisms to establish themselves deep within the material, making specialist treatment essential for a long-lasting restoration. We applied a specialist pre-treatment to kill the organic growth and begin breaking down the embedded biological contamination. This loosens stubborn black spot and lichens, allowing them to be removed far more effectively during the cleaning process. The patio was deep cleaned using professional high-pressure surface cleaning equipment before receiving a second specialist treatment. A final cleaning pass then removed the remaining contamination, restoring the sandstone without unnecessary damage. To complete the restoration, we applied Chiltern EverGuard™. The treatment penetrates into the sandstone to eliminate remaining spores beneath the surface while providing 12–24 months of protection against the regrowth of black spot, algae, moss and lichens.

The patio has been fully restored, revealing the natural colour and character of the sandstone once again. With Chiltern EverGuard™ protection in place and simple ongoing maintenance, black spot and lichen are far less likely to become established again, helping the patio stay cleaner for longer.