Waterproofing failures are a frequent cause of construction-related insurance claims, according to insurance companies. The application of membranes on interior or exterior surfaces serves as a protective barrier against water infiltration into building structures.
However, the installation of waterproofing membranes is a labor-intensive and technical process that requires the expertise of remedial waterproofing consultants and qualified installers.
Unfortunately, a staggering 90% of waterproofing membrane failures can be attributed to poor workmanship, making it the primary cause of unsuccessful waterproofing installations.
Table of Contents
1. Inappropriate Product Choice and Incompatible Waterproofing Membrane
Choose an unsuitable membrane for the substrate application or use one that doesn’t mesh well with other products to guarantee success in waterproofing application. Inappropriate primer use could cause membrane debonding and thus end the waterproofing system’s efficacy.
Care should be taken when reviewing product safety data sheets or product application sheets in order to use products recommended by their manufacturers for waterproofing, as any deviation could void any guarantees related to waterproofing. Attempts at waterproofing by other means might result in damage that voids these guarantees.
2. Application on an Uneven Surface
Before installing a waterproofing membrane, it is crucial to ensure that the substrate’s surface is level. If the membrane is applied to an uneven surface, gaps may form between its layers or the membrane may not create a tight seal with the substrate. This allows water to seep between the membrane and the substrate, compromising its effectiveness. In such cases, it is recommended to use screed or employ professional waterproofing methods to address the unevenness of the substrate.
3. Application on a Wet or Damp Surface
Applying a waterproofing membrane on a damp or wet substrate can significantly impact its ability to adhere to the surface. The presence of water creates a gap between the membrane and the substrate, leading to debonding of the membrane from the surface. It is crucial to ensure that the substrate is dry before proceeding with the membrane installation to avoid such issues.
4. Application on a Polluted Surface
Proper cleaning of concrete surfaces is crucial in order to remove contaminants that might impede the adhesion of waterproof membranes, including dust, curing chemicals, form oils, wax, and mold. Unfortunately, contractors and applicators often skip proper cleaning in an effort to save time and labor, leading to contamination between the waterproof membrane and surface that leads to debonding of waterproofing membranes.
5. Insufficient Preparation
Inadequate preparation of the surface before installing the waterproofing membrane can lead to debonding. This often occurs when applicators cut corners on using primers or fail to apply them consistently. Proper surface preparation, including the use of primers, is crucial for ensuring a strong bond between the membrane and the substrate.
6. Uneven or Inadequate Liquid Membrane Application
Uneven application of a liquid waterproofing membrane can result in an inconsistent thickness of the waterproofing layer. Some waterproofing membrane products require multiple applications, and failure to apply them properly can compromise their effectiveness. Thinner portions of the membrane may degrade more quickly, reducing the overall durability of the waterproofing system.
7. Incorrect Overlaps
Incomplete bonding overlaps between membrane sections can jeopardize the integrity of the waterproofing layer. If the membranes separate at the seams, water can seep through and penetrate the concrete, causing potential damage.
8. Trapped Air (Stinging)
Under-primer coverage on surfaces may lead to the accumulation of trapped air below a membrane and cause debonding and blister formation on its surface. When this happens, air can escape, which allows water ingress into concrete structures through any potential punctures in its waterproofing layer, causing leakages into concrete structures and eventually becoming leaks within them. This situation must be prevented.
9. Poking and Tearing
Waterproofing membranes are prone to damage during subsequent phases of the construction process. Activities like pipe installation, backfilling, and concrete drilling can result in punctures. Moreover, movement, settlement, or expansion joints in the building can cause tearing of the membrane. Both puncturing and tearing compromise the integrity of the waterproofing layer, leading to failure.
10. Deterioration/Weathering
Over time, many waterproofing membranes deteriorate due to factors such as exposure to UV light, harsh weather conditions, aggressive groundwater, or chronic ponding. These conditions cause the waterproofing layer to separate and the membrane to fail, rendering the waterproofing system ineffective.
In conclusion, understanding the common reasons for waterproofing membrane failures is essential to avoid costly construction issues. Proper product selection, surface preparation, application techniques, and protection against damage are all vital factors in ensuring the long-term effectiveness of waterproofing membranes.
By addressing these common pitfalls, construction professionals can significantly reduce the risk of waterproofing failures and associated problems.
