There are many reasons why you should choose a liquid membrane for waterproofing. But even the best products and methods can fail if the wrong steps are taken during preparation or application. At SEMCO Works Australia, we’ve seen it all; and we want to help you avoid the mistakes that lead to damage and expensive repairs.
In this article, we’ll break down the most common reasons liquid waterproofing fails and how to make sure your next project is done right the first time.
1. Poor Surface Preparation
The success of any liquid waterproofing membrane starts with the substrate. If the surface is dirty, oily, dusty, or uneven, the membrane might not bond properly. This can lead to peeling, blistering, or water finding its way underneath.
Common prep mistakes to avoid:
- Skipping cleaning or degreasing
- Applying over damp or contaminated surfaces
- Ignoring cracks or structural defects before coating
2. Incorrect Product Selection
Not all waterproofing products are created equal, and not all are suited for every job. Using the wrong membrane for the environment or substrate can cause premature failure.
For example:
- Choosing a membrane not designed for UV exposure on a rooftop
- Using a product with low flexibility on a surface prone to movement
- Selecting a coating that can’t handle chemical or saltwater exposure
Always match the product to the job’s specific needs.
3. Inconsistent Application Thickness
Liquid waterproofing membranes are designed to work at specific thickness levels. Too thin, and it won’t provide a proper barrier; too thick, and it can crack or take too long to cure. Additionally, the layers need to be applied evenly.
Signs of poor application:
- Patchy coverage
- Visible substrate through the coating
- Uneven film build across the surface
4. Rushed Curing Time
Curing is when the membrane develops its full strength and waterproofing properties. If the surface is walked on, exposed to rain, or covered too soon, the membrane can be compromised.
Typical causes:
- Tight project deadlines
- Weather changes during curing
- Ignoring manufacturer’s recommended drying times
Plan your project around the weather and allow extra curing time for cold or humid conditions.
5. Ignoring Structural Movement
Buildings move from temperature changes, settling, and vibrations. If the waterproofing system can’t accommodate this movement, it will crack and allow water in.
How to prevent this:
- Use flexible liquid membranes where movement is expected
- Incorporate reinforcement fabrics in high-stress areas
- Regularly inspect expansion joints and repair as needed
Final Thoughts: Do It Once, Do It Right
Waterproofing failures are costly — not just in repairs, but in potential structural damage and downtime. By choosing the right product and ensuring proper installation, you can protect your investment for years to come.
Ready to waterproof with confidence? Shop Liquid Membrane.