Our system has noticed that you are based in , but the current country setting is . Select country
Testing cementitious waterproofing membranes: crack bridging beats elongation
To create a durable water barrier, waterproofing membranes must be flexible enough to accommodate structural movement and bridge fine cracks. That’s why they should be modified with VINNAPAS® dispersible polymer powder. However, while various test methods exist to assess flexibility, not all provide results that reflect real-life conditions. Let’s take a look!
Traditionally, the flexibility of waterproofing membranes is tested with a generic elongation test used for many elastic materials such as rubber. For this test, specimens are cut from the membrane, clamped into a testing device and stretched until they break. The problem: in real-life applications, waterproofing membranes are never exposed to these kinds of elongation forces. That’s why, at WACKER, we favor the crack-bridging test according to EN 14891.
How the crack-bridging test works
The crack-bridging test simulates conditions in actual buildings. The waterproofing membrane is applied to a mineral substrate and exposed to defined cycles of heat, cold and water immersion. After this controlled aging process, researchers create a crack in the substrate and measure the membrane’s ability to maintain its waterproofing function.
Watch our video to learn more about the crack-bridging test.
Flexibility alone is not enough
In waterproofing membranes, flexibility is essential, but it’s only a means to an end. The ultimate question is whether the membrane can bridge cracks and maintain its integrity under stress. Elongation tests measure stretching capacity in isolation. The crack-bridging test, on the other hand, evaluates the membrane as part of an applied system – providing more reliable insight into its real-life performance.
“The elongation capacity of an isolated waterproofing membrane sample does not predict its actual performance. The crack-bridging test simulates real conditions and delivers more meaningful results.”
Different climatic conditions mean different requirements for waterproofing membranes
How universal are standard conditions?
The crack-bridging test described in European Standard EN 14891 outlines how to evaluate crack-bridging ability under standard conditions (23 °C). But the methodology is easily adaptable to different climates, including regions with extreme heat, cold, humidity or monsoon conditions.
“The crack-bridging test allows us to measure crack-bridging ability under any conditions, which makes the test universally applicable and interesting for regions with differing climates such as the Middle East, India and Asia.”
In our Technical Competence Centers, we develop, test and optimize customer formulations for regional and cross-regional markets.
Local expertise makes the difference
When it comes to the conditions that waterproofing membranes are exposed to every day in different regions of the world, who knows better than the people who live there? The experts at our Technical Competence Centers in Southeast Asia, the UAE, India and Germany are a treasure trove of valuable regional knowledge. By understanding local climatic challenges, they can define the most relevant testing parameters. While the crack-bridging test follows the European standard, its conditions are adapted to meet local requirements.
“Local climate conditions can vary dramatically, and only those who work on site truly understand their impact on construction. Our regional teams ensure that the crack-bridging test is tailored to the real challenges faced by our customers – wherever they build.”
Enhanced performance with VINNAPAS®
One-component (1K) waterproofing systems modified with VINNAPAS® dispersible polymer powders reliably pass the crack-bridging test according to EN 14891. Polymer modification significantly improves crack-bridging capability, making waterproofing membranes more resilient to movement. In addition, because systems modified with VINNAPAS® are easier to mix on site and help reduce packaging waste, they contribute to more efficient and sustainable construction practices.
Learn more about our solutions for waterproofing membranes
Related:
