Biological Growth

Biological growth

Biological attack such as algae, fungi and mould growth are common in tropical areas. Concrete surfaces collect dirt and retain moisture, which encourages biological growth. Moreover, common problems such as water stagnation for water flowing from the planter of VGS, results in biological waste secretions in existing building structural elements, where one would be able to see the dirtying and soiling of walls. This can result in a possible weakening of building structural integrity. Main cause would be the lack of regular maintenance in cleaning these structural elements.

• Biological growth on structural wall

Dirtying and soiling of walls were seen in the VGS that is affected by shade and moisture, thus causing biological growth on the surrounding wall. Moreover, leaking of biological waste or rotting of dead vegetation section over time from upper levels that drip to the base of VGS could also spur biological residue on walls. Waterproofing and glossy paint application can be done to prevent such from happening, aside from regular cleaning and maintenance.

• Fungi growth on suspended beam/ledge

Due to the abundance of organic matter from the vegetation and the relatively higher humidity level have allowed fungus to proliferate and thrive on the suspended beams/ledge where they have deposited. A high humidity and rainfall volume together with the presence of dirt and organic spore, organic growth results on the beams and ledges. Water will adhere like a thin film, with spores and dirt to be trapped within it. Fungi growth would thus thrive on such conditions, resulting unsightly patches of fungus to spread which will lead to deterioration of the paintwork.

• Algae growth on finishes

Water stagnation if left untouched for a long time would spur growth of algae, leaving unsightly algae stains on walls and finishes. There are cases where algae thrive due to water leakages on green walls that have air-conditioned compressor units installed. With the necessary humidity, temperature and shade, algae thrives after their spores are transferred by wind to these surfaces and are seen on most of the wet surfaces, characterised by green stains that are prominent on concrete walls. This is consistent with the vertical stains, which indicated that water likely flowed down from the plant boxes. As the edge of these ledges that do not have a downward sloping gradient and thus provided a suitable environment for algae to grow due to instances of water ponding on the ledges.

• Weed growth on walls

Weed also can sprout out from cracks and crevices of walls that are accumulated with soil and dust particles as well as other nutrients. With that, the cracks of walls are weeded and filled. Such growth not only undermines the aesthetic value of the facade, but also may undermine the structural integrity of the building. Though biological growth on walls are not usually structurally damaging, they do disfigure wall and make corrective treatment difficult and costly.