We were recently contacted by a Mr W. who owned a 4 bedroomed detached property in Four Oaks, West Midlands.

The property had been given a white, textured render coating (Andura) several years ago and although structurally the render was holding up ok, it had become greyed over time and had lost it’s original, bright whiteness.  Some areas had black vertical streaks which were particularly unsightly.

We arranged to visit the property and discuss the issue with the homeowner who pointed out various areas of particular concern.

Localised tests were carried out on the surface to determine the cause of the greyness.  It was ascertained that the cause was an airborne algae which had become attached to the render and over time, was spreading and getting worse.

The recommended treatment for this type of black algae was a sodium hypochlorite based cleaning agent with added surfactants to help it adhere to the surface.

Exact quantities of the cleaning agent were diluted 9:1 with water.

Prior to cleaning taking place, all plant pots were relocated as well as other vegetation/windows/conservatory/lead flashings and a fabric awning were saturated fully with water to keep then protected during the cleaning process.

The pre-measured cleaning solutions was transferred to the render surface using a telescopic pole with a soft bristled brush at the end.  The solution was brushed into the surface and allowed to dwell for 30 minutes before being rinsed off with water.  Certain areas of high infestation were given a second treatment to remove all traces of the black algae.

After the treatment had taken place, all surrounding areas were hosed down to make sure no remnants of the cleaning solution remained.

The windows were given a thorough clean and the property was left in a vastly improved condition.

Both I and Mr W. were very happy with the results achieved.