Preventing Delamination of Concrete Overlays from Water Vapors

concrete delamination concrete overlay

The goal of concrete overlays is to create durable, aesthetically pleasing surfaces that stand the test of time. However, there are certain challenges that can make it difficult to achieve this goal, including delamination caused by water vapors. Delamination occurs when the bond between the overlay and the concrete surface underneath, also known as the substrate, weakens or fails. This may result in cracks and reduced longevity.

In this comprehensive guide, we’ll explore the causes of delamination, plus present some proven strategies to prevent this issue and ensure your concrete overlay stays in good condition.

Understanding the Root Causes of Delamination

There are a few different reasons that delamination may occur, including exposure to water vapor. Moisture is a major antagonist in the delamination process because it can wreak havoc on the bond between the concrete overlay and the substrate underneath. 

The following elements contribute to delamination:

  1. Inadequate surface preparation: Properly preparing the existing concrete surface before applying the overlay is of utmost importance. Improper preparation, including failure to thoroughly clean, etch, or profile the surface, can allow water vapor to penetrate, leading to delamination.
  2. Moisture in the substrate: If the underlying concrete surface contains excess moisture, it can migrate upward into the overlay through a process called capillary action and exert pressure that could cause the overlay to separate.
  3. Improper mix design: The mixture of materials used for the overlay must account for environmental conditions, including moisture levels and exposure to water vapor. An inappropriate mix can compromise the overlay’s ability to resist moisture.
  4. Lack of moisture mitigation: If you live in a region with high humidity or a high water table, you may need to take moisture mitigation measures in order to prevent water vapor from rising through the substrate.

Proven Strategies for for Preventing Delamination

Now that we’ve presented some of the causes of delamination, here are some tips to prevent it from affecting your concrete overlays.

Thorough Surface Preparation

The importance of thorough surface preparation prior to applying the concrete overlay cannot be overstated. Proper preparation is the foundation for a successful overlay installation. The surface must be free of dirt, debris, and other contaminants. It should also be roughened using techniques such as diamond grinding, acid etching, or shot blasting to provide a suitable texture for the overlay to bond to. 

Environmental Considerations

When planning your projects, you should always consider the local climate and environmental conditions. You may need to adjust your designs or use different materials to accommodate the specific moisture challenges that come with the region.

Moisture Testing

Moisture tests are an indispensable tool in assessing the readiness of the substrate for overlay installation. You can use a moisture meter to accurately gauge the material’s moisture content. 

In addition, you may also want to consider performing a plastic sheet test to further help you identify moisture problems. Simply place a plastic sheet on the concrete, and if it develops a layer of condensation, moisture mitigation may be necessary.

Moisture Mitigation

In areas where high moisture levels or exposure to water vapors are a concern, implementing moisture mitigation measures is a smart choice. To prevent delamination and create a barrier between the substrate and overlay, use epoxy moisture barriers and moisture-resistant primers.

Choosing the Right Material

Installation of Pro Bond Ultra

Not all overlay materials are suitable for use in areas that will be exposed to water vapors. Some are more moisture-resistant than others, so it’s important to consult with your overlay material supplier for help selecting products that will suit your needs and result in a successful installation.

Proper Curing

The development of concrete strength, durability, and resistance to delamination hinges on proper curing. Make sure you follow the manufacturer’s guidelines for curing to ensure your concrete overlay reaches its full potential and remains resilient against exposure to moisture from water vapor. 

Regular Maintenance

After installing the concrete overlay, you will need to maintain it by periodically applying sealers. This creates a protective barrier on the surface of the concrete and reduces the risk of moisture infiltration, enhancing the overlay’s lifespan.

Concrete Overlay Materials from Stone Edge Surfaces

Whatever products need to create beautiful concrete overlays, Stone Edge Surfaces has the solutions to help make the process quick and simple. Our materials can be used for both vertical and horizontal overlays, and we even provide training resources such as videos and blogs detailing tricks of the trade to help you find maximum success with every installation. 

To learn more about our products and get answers to all your questions about specialty concrete applications, contact us today.

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