When a building leaks, it is often difficult to identify where water has got through the cladding, as water can track within the structure. This is usually through the effects of gravity, which can move water a significant distance from where it first entered.
Investigations of failed buildings have identified that the majority of leaks occur through wall claddings, and a number of high-risk details and design features have been identified. While roofs have not tended to feature in failure statistics, they still need to be detailed and constructed accurately.
The most common areas where water has been found to penetrate the cladding are at:
- joints and junctions at cladding penetrations (particularly around windows and doors)
- junctions between different cladding materials
- joints in the cladding
- parapet and solid balcony walls
- service penetrations (pipes and meter boxes)
- structural penetrations
- movement cracks in the cladding (particularly at joints and in monolithic finishes)
- roof-to-wall junctions
- absorption through the cladding.
While many leaks are a result of rain being driven against a building exterior at variable pressures, angles and directions (by wind), many buildings have leaked in calm conditions where water has entered the building through the effects of gravity (particularly when water has been allowed to pond on flat surfaces).
Updated: 9 September 2014