Roof Moss Removal and
Sandstone Patio Cleaning
Berkhamsted, Hertfordshire

The roof at this Berkhamsted home was carrying established moss on every elevation — along every course, through the valley and heaviest towards the eaves — with black algae and lichen across the tile surfaces.

The roof was also showing its age, with raised and slipping tiles in places. That set the approach before any work began: as little mechanical stress on the tiles as possible, letting heat and treatment do the work rather than pressure.

The drone survey revealed black algae and moss on every elevation — the tiles, the valley, the chimney slope and the guttering, all seen up close before a method was chosen.

It also let us assess the access requirements for this tricky property, the roof angles above all, so the right equipment was chosen before work began. With an ageing roof and raised and slipping tiles in places, that meant the lowest possible pressure rather than force.

Two Chiltern Surface Co technicians worked at the same time, each on their own system — twin engines running together, so both could work at the lowest pressure possible. Two different access methods put the whole roof within reach: a tracked spider lift, close to every outer elevation, and a scaffold tower in the courtyard.

The established moss was removed with steam at very low pressure. Heat does the work, not force, so the tiles are under as little stress as possible. The most heavily bonded lichen was treated rather than forced from the tiles: it dies back and weathers away naturally. The moss and debris were collected and removed from site.

Chiltern EverGuard™ is a system, not a single product. At its heart is a biocide that penetrates the pores of the material, kills the growth living inside and inhibits regrowth, applied by a method we have developed ourselves. It was applied to the complete roof, the sandstone and the treated brickwork.

It keeps working after it goes on: residual black spot and the treated lichen continue to die back and weather away over the weeks that follow, so the surfaces keep improving after the team has left.

Chiltern Surface Co carried out this roof moss removal and sandstone patio cleaning in Berkhamsted, Hertfordshire. We also offer patio cleaning, driveway cleaning, roof cleaning and roof moss removal across Buckinghamshire, Oxfordshire, Berkshire, Hertfordshire and Surrey, including Princes Risborough, Thame and Watlington.

Moss and black spot live in the pores of a roof tile or a stone, not just on its surface, which is why a lasting result is a staged process — the right access, controlled cleaning at the lowest effective pressure, and protection with Chiltern EverGuard™ — rather than a single pass with a pressure washer.