Waterstops in Wet Areas: A Critical Element for Success
What Exactly is a Waterstop?
According to the Australian Standard for internal wet areas (AS 3740:2021), a waterstop is a "vertical extension of the waterproofing system forming a barrier to prevent the passage of moisture in the floor or vertically in a wall." Think of it as a dam that keeps water contained. This can be achieved through various means, including:
Specialised extrusions: Typically made from folded aluminium, these are fixed to the floor at the shower entrance or wet area threshold.
Hobs and nib walls: These are raised sections act as built-in barriers to contain water within the shower area.
Other integrated barriers: Any element designed to prevent water migration as part of the overall waterproofing system.
Why are Waterstops so Important?
Waterstops are crucial because they:
Prevent leaks: They stop water from seeping under tiles, damaging flooring, and causing structural damage over time.
Protect surrounding areas: They safeguard adjoining rooms and prevent costly repairs to carpets, walls, and ceilings.
Maintain hygiene: By containing moisture, they help prevent mould growth and maintain a healthy environment.
Key Considerations for Effective Waterstops:
Material selection: While the standard doesn't specify a particular material, it does provide guidance that it should be rigid, corrosion-resistant, and durable. Aluminium extrusions are a common and effective choice.
Example of a metallic waterstop.
Proper installation: Waterstops must be securely fixed to the floor and integrated with the waterproofing system to create a continuous, watertight seal. This is especially important where the waterstop meets the wall.
Height: The waterstop should extend to or above the finished floor surface, depending on the specific application and type of waterstop used.
Waterproofing System Integration
It's crucial to remember that the waterstop is an integral part of the overall waterproofing system. The waterproofing system includes:
Primer: Prepares the substrate for optimal membrane adhesion.
Waterproofing membrane: The primary barrier against water penetration.
Reinforcing fabric: Adds strength and durability to the membrane (if required by the supplier).
Sealants: Used to seal joints and create fillets as part of the overall installation.
Waterstop: The vertical barrier that completes the system.
Remember that the standard does not tell us who should supply the waterstop, it requires one is installed and that it is considered part of the waterproofing system
Responsibility for Installation
AS 3740:2021 considers the waterstop an integral part of the “waterproofing system”. Therefore, it's the responsibility of the waterproofing contractor to ensure its correct installation and integration with the waterproofing system.
Visual Example
Refer to Figure 4.9.1 (A) in AS 3740:2021 for a clear illustration of how a waterstop should be integrated with the waterproofing system at a door threshold. This diagram highlights the importance of a continuous connection between the waterstop, the membrane, and the wall substrate.
Example illustration of how a waterstop should be integrated with a waterproofing system at a door threshold.
By understanding the importance of waterstops, ensuring their proper installation and integration with the waterproofing in accordance with AS 3740:2021 you can create a robust and reliable waterproofing system that protects wet areas from costly water damage and possible litigation.
If you have any questions or would like to explore how AWC can help to protect your assets from waterproofing damage, get in touch.