RENDER CLEANING
CONTROL RED & GREEN ALGAE ON WALLS
HARD SURFACES, SYNTHETIC PICTHES, TENNIS COURTS
In the past 3 decades or so self finished renders became popular among architects. There are good reasons for this, both from an architectural and practical point of view. For the designer can offer different type of styles from: smooth, textured, mica sparkles or colour pebbles. With low maintenance been and added benefit: Every now and again cleaned, but never painted again. However the introduction of wall insulation has reduced the cleaning periodicity. Broadly, less heat transfer through the wall means a moister render and more algal growth. Published studies show that a temperature decrease of 2 degrees leads to increasing the relative humidity of the render by approximately 10%.
Biocide purity: It is particularly critical to use a high purity quaternary ammonium on render. Alternative biocides based on bleach or quaternary ammonium's containing impurities/solvents may permanently affect the appearance of the rendered surfaces .
Timing: We apply a high purity quaternary ammonium.
The treatment is not like removing the algae using a pressure washer it
will take time for the algae to naturally wear aware.
Algae & Cyanobacteria
Phototrophic microorganisms (algae, cyanobacteria) can grow on stone surfaces or may penetrate the pore system of the stone itself. Phototrophic microorganisms have a direct effect on the deterioration of stone due to their pigments which cause an aesthetically detrimental effect.
Filamentous cyanobacteria (Nostoc sp, Leptolyngbia sp., Stigonema ocellatum) and green algae (Desmococcus olivaceus and Haemaotococcus pluvialis) are capable of forming dense mucous-like layers on surfaces which produce characteristic colourations on the substrata.
Nostoc. sp can produce blackish-green pigmentation which leaches into the substrate on which it is growing.
The algal species Desmococcus olivaceus produces bright green colouration of buildings as shown below.
Cyanobacteria Nostoc sp.(Devil Spit)
can resist drought.
Haemaotococcus pluvialis
Desmococcus olivaceus
Filamentous Cyanobacteria
Haemaotococcus pluvialison on a building
Green Algae