Case 2

Introduction

Mould Growth on Basement Wall

Type of Building: Carpark

Mould has spread widely over the paint coating of the concrete wall in the basement. Fungi may grow on damp/moist biodegradable finishing materials. The moisture content of the indoor environment is the primary environmental factor in determining the extent of fungus growth. The most important moisture parameter for the growth of microbial organisms is the water activity (or relative humidity, RH) of the substrate instead of the moisture content of the material. However, according to many researchers, the measurement of humidity might not be adequate when assessing the risk of mould growth.

The main moisture source appears to be the water seeping in from the external wall of the basement. Water seepage through these mortar joints were evident since water stain marks has formed on the wall. The lack of provision for drainage, together with ineffective waterproofing, may cause the pressure from the soil water to drive the water into the wall surface.