Why Is My Balcony Leaking?

Over the course of several surveys, it has been found that balconies are a major source of water leakage issues. If you live in a multistory house or in an apartment, then you may have found yourself wondering at some point as to why the balcony is leaking water. Was it due to a heavy storm that flooded the balcony or improper waterproofing works done at the construction of the building? In this article we aim to explore why balconies are particularly vulnerable to water leakage and recommendations for improving waterproofing methods.

For starters, residential multi-story and multi-dwelling buildings do experience a higher frequency of building defects. Most commonly, these defects are related to waterproofing failures and consequently water leakages. But what exactly makes the balconies on such buildings more vulnerable to water leakages? The answer lies in how balconies are often constructed with minimal falls to the substrate.

Balconies’ waterproofing membranes need to be able to withstand “standing water” or minor ponding that results from heavy rainfall. Given the relatively flat nature of balconies, water can be expected to accumulate in select areas. Moreover, this problem is exacerbated by home owners who do not take the effort to manually drain their balcony after rainfall. If a balcony is constructed with minimal fall, then water will ingress through the applied grout, leading to moisture ponding between the tiles and the membrane. If the installed membrane is unable to withstand the moisture ponding, then the membrane material will breakdown when typical thermal expansion and contraction of the building occurs.

Balconies are also under constant exposure to UV rays from sunlight, wind and rain. These forces allow for water penetration beyond the top surface layer and via exposed edges. Over time, the balcony structure deteriorates, enabling significant defects to occur such as concrete spalling. Additionally, the rate of deterioration is enhanced when balcony surface transitions are poorly planned.

What then should home and apartment owners do when they discover a water leakage in their balcony? If a water membrane has been proven to be defective, re-grouting or surface sealing will not be effective in the long run. These basic band aid methods will help to temporarily stop or slow down water penetration but are vulnerable to grout cracking when the building expands or contracts.

Instead, a professional waterproofing company should be engaged for leakage repair works. A full replacement of the waterproofing membrane will be needed, this time taking into account the calculated fall of the balcony. Additionally, proper tile detailing may also be needed to ensure that balcony surface transitions reduce the chance of moisture ponding.

It must also be mentioned that this situation demands urgency and that home owners should not delay requesting for help. Water, if given time to penetrate, is capable of being a highly destructive force towards your building’s structural integrity.