All construction materials have a finite lifetime. With bathrooms, and shower areas in particular, the expiration of that life time is evident when leakage occurs into other areas of the unit, common property, or both.
Apart from burst water pipes, washing machine/dishwasher hoses, the most common water leakage problem is associated with shower recess leakage in bathroom and ensuite areas, where moisture is penetrating a wall or the base of the shower area.
Where a wall is exhibiting water penetration on the opposite side of a shower area, the wall could be:
an internal wall (e.g. between a bathroom and bedroom) which is the private property of the lot owner; or
a perimeter wall which could be either an external wall or a wall adjoining the common property such as an access hallway in a block of units or the dividing wall between two units.
The problem is usually most evident when paint starts pealing, most commonly at the lower end of the wall on the other side of a shower recess wall.
Whether the repair of the leaking shower area is the responsibility the Owners Corporation or the responsibility of the lot owner will depend upon the source of the problem which could be a leaking pipe or taps behind a common or private wall, a failed waterproofing membrane, defective grouting or broken or cracked tiles. Whilst the cause could be any or all of the above the overriding criteria for determining responsibility is where the source of problem is emanating from. Whether the source of the problem is within the air space of the lot or in the air space of common property will determine whether the proprietor of the lot or the Owners Corporation is responsible.
As an example, if the leak is only through a wall and that wall is an internal dividing wall then the proprietor of the lot will be responsible for the repair, whether or not the common property is subsequently affected by the leak.
If the problem is in a common wall or the floor area, both of which are common property, then the Owners Corporation will be responsible.
Often it is not immediately apparent where the source of the problem may be located and will require investigation, in which case there should be an agreement between the Owners Corporation and the lot owner prior to work commencing to bear or share the cost depending upon the source of the problem or, preferably the Owners Corporation will have registered a cost recovery by-law so that when the investigation identifies the source of the leakage as either private property or common property, the party responsible for the cost of the repair will be able to be determined.