Research shows that 23% of serious building defects link to waterproofing problems, that can lead to health, physical and even psychological harm. The effectiveness of waterproofing systems fundamentally depends on compatibility between substrates, primers, waterproofing membranes, tile adhesives and sealants and how these products interact with each other.
Ensuring the waterproofing system is compatible
System compatibility extends beyond individual component testing. A complete compatibility testing approach evaluates material interactions within the entire waterproofing system. Statistics reveal that ‘buildings with defects, more than half (63%) included waterproofing as one of the defects’ which can incur significant amounts of money and time to fix. This fact emphasises the need for proper testing before installation.
Successful waterproofing relies on compatibility testing between:
· Primers and surface materials
· Waterproofing membranes and substrates
· Tile adhesives and waterproofing systems
· Topcoats and underlying layers
· Sealants and waterproofing membrane/adjacent materials
Key test methods that highlight compatibility between the waterproofing system:
AS ISO 13007.5: Liquid-applied waterproofing membranes for use beneath ceramic tiling bonded with adhesives
2. AS ISO 13007.6: Sheet waterproofing membranes for use beneath ceramic tiling bonded with adhesives
3. Adhesion Testing: Pull-off various substrates
4. Peel Adhesion Testing: evaluates the bond strength of flexible membranes to various substrates, focusing on shear adhesion. Unlike rigid materials, flexible membranes stretch and deform rather than fracture, making this test critical for assessing their actual performance and durability.
5. Exposure Response: Testing compatibility after being exposed to various chemicals and conditions
6. Performance Verification: Assess system behaviour under simulated conditions
Testing Procedures for Waterproofing Membrane Compatibility with Tile Adhesives
Testing of waterproofing membranes and tile adhesives, after chemical or exposure testing AS ISO 13007.5 or AS ISO 13007.6 are among the few test standards that assess compatibility within a system and can provide important data on the performance and potential longevity of leak free buildings in Australia and New Zealand. The test standards AS ISO 13007.5/.6 are not only recognised in Australia but also internationally, to benchmark against globally recognised systems
Key exposure tests in AS ISO 13007.5/.6 that assess compatibility include:
· Tensile adhesion
· Tensile adhesion after water contact
· Tensile adhesion after heat aging
· Tensile adhesion after freeze-thaw cycles
· Tensile adhesion after contact with lime water
· Tensile adhesion after contact with chlorinated water (optional)
In addition to testing the compatibility of waterproofing membranes with tile adhesives, AS ISO 13007.5 (liquid membrane) and AS ISO 13007.6 (sheet membrane) also include standalone tests for waterproofing membranes. These tests involve:
Water Impermeability: In this test method, the waterproofing membrane is subjected to 1.5bar top-down water pressure for 7 days to assess its capability to resist water ingress through to the concrete layer. The waterproofing membrane is applied over the top of a concrete block and weighed before and after exposure to water pressure. If the weight gain after 7 days of exposure is ≤3.0 grams (for sheet membranes) and ≤20 grams (for liquid membranes), the membrane is considered compliant.
· Crack Bridging: This test method evaluates the membrane’s ability to bridge a crack. A membrane is coated over a concrete block, with a forced crack in the concrete after the membrane is cured, the concrete block is then placed in a UTM and elongated to
determine the waterproofing membranes capacity to bridge a crack. Bridging a crack of ≥0.75mm is considered compliant.
The performance and compatibility of a system are critical factors that help determine how different components work together. While individual performance testing for each component is important, compatibility also plays a crucial role as an indication that the overall system functions efficiently and reliably as a cohesive unit.
Material incompatibility has proven to cause costly waterproofing failures. Therefore, adopting a test approach that includes complete system compatibility helps identify the risks of such failures and corrective actions needed to provide reliable protection against water damage.
