ARDEX ANSWERS
Sheet vs Liquid Waterproofing Membranes: What You Need to Know
In this episode of ARDEX Answers, Technical Services Advisor Chris Brady joined Monique Fenech to explore a frequently debated topic in waterproofing: sheet membranes versus liquid membranes. Both systems have a place in Australian construction, but choosing the right one depends on your application, substrate, and project conditions.
Understanding the Two Membrane Types
Sheet membranes come pre-formed and are often self-adhesive or heat-applied. They offer consistent thickness and are ideal for applications where immediate coverage and uniformity are required.
Liquid membranes are applied in liquid form and cure into a seamless membrane. They’re versatile and ideal for irregular shapes, tight corners, or detailed areas that are difficult to address with sheet membranes.
When to Use What
According to Chris, liquid membranes are commonly used in internal wet areas like bathrooms due to their flexibility, ease of application, and detailing capabilities. Sheet membranes are more common in external applications—such as balconies and podiums—where consistency in membrane thickness and elongation properties are paramount.
Challenges & Misconceptions
One key challenge discussed is substrate preparation. With liquid membranes, substrate priming is critical for adhesion and performance. Sheet membranes can be more forgiving in this regard but require cleaner surfaces for full bond adhesion.
Monique and Chris also addressed a common misconception: that thicker equals better. In truth, performance depends more on membrane properties and correct application than on thickness alone.
ARDEX Support
ARDEX provides both types of membrane systems, along with training and technical bulletins to ensure correct use. Their Academy and hotline are valuable resources for applicators navigating this decision.
For more guidance, contact the ARDEX Technical Hotline at 1800 224 070.