Case 3

Bio-growth: Fungi

Introduction

Fungal growth has spread widely over the ceiling of the toilet of a residential unit in this case. There are a variety of fungi which can grow in hot and moist environment and some of them are harmful. The viability of fungal growth on building materials depends on the characteristics of the material, humidity and temperature. The moisture content is the primary environmental factor to determine the extent of growth of fungus. The most important moisture parameter for the growth of microbial organisms is the water activity (or relative humidity, RH) of the substrate instead of moisture content of the material. However, according to many researchers, when assessing the risk of mould growth, the measurement of humidity might not be adequate. More often than not, temperature might also be important in determining the extent of mould growth.

Fungi on a bathroom ceiling can develop for a number of reasons. The ideal warm, moist habitat for the spores to grow, for instance, can be created when vapor from hot water rises to the ceiling and settles there. Other problems can result in fungi on bathroom ceilings in addition to those activities in the bathroom that allow infestations to begin. Water damage may result from a leaking roof or a busted pipe in the room above the bathroom. These create the ideal environment for spores to grow when coupled with the warm air rising from the bathroom. Additionally, mold develops in poorly ventilated places. Spores begin to form when the moisture stays too long. They will also keep growing as long as there is moisture.