7. Investigative thresholds and practical limitations

7. Investigative thresholds and practical limitations

The Joint Office’s powers are significant but not unlimited. One major limitation is the 35% moisture-content threshold. The Joint Office generally will not proceed with a formal investigation where the moisture content is below 35%, as such cases are regarded as having no clear evidence of a public health nuisance. Furthermore, the Joint Office will cease investigation if the seepage becomes mild (dropping below 35%), improves significantly, or if the source cannot be identified after all feasible tests. 

Another important limitation is that the Joint Office’s investigations are generally non-destructive. The Joint Office does not usually break open floors, walls, or pipes to identify hidden defects. Instead, it relies on non-invasive methods such as moisture measurement, infrared thermography, colour water testing, and, where feasible, advanced technologies such as microwave tomography. While these methods are useful, they may not identify the source in complicated cases. 

Rainwater seepage is another area where the Joint Office’s role is limited. Seepage caused by rainwater penetration through roofs, external walls, or windows is generally not treated as having public health implications under the PHMSO. As a result, the Joint Office usually does not pursue such cases through the statutory nuisance process. Instead, they may be referred to the Buildings Department if they involve building safety or maintenance concerns, the Water Supplies Department if water wastage is detected. The Joint Office may also advise the Incorporated Owners to engage private professionals for repairs, or leave them as matters for private resolution between owners.