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Unmasking the Myth – Does Silicone Render Crack?

Have you ever noticed cracks on the walls of your home, office, or any other building? It’s not just an unsightly blemish but can also lead to bigger problems if left untreated. Traditional renders have been known to crack easily, leaving building owners with hefty repair bills. But what about silicone render? Can silicone render crack, or is it a myth?

As the name suggests, silicone render is a type of render made with silicone. It has become increasingly popular in the UK construction industry due to its many benefits over traditional renders. But despite its growing popularity, there are still misconceptions about whether or not it can crack.

This blog post aims to unmask this myth and provide facts about silicone render.

 But first, let’s understand what silicone render is. Simply put, it’s a type of decorative finish that’s applied to the external walls of a building. It’s made up of silicone, resins, and mineral fillers. This composition gives it a unique set of properties, making it a popular choice in the construction industry.

Now, you might be wondering why we’re talking about silicone render and cracking. Well, that’s because cracking is a common problem associated with traditional renders.

And when building owners hear about silicone render, they often assume it’s a solution to this problem. But the truth is, silicone render can also crack if not applied correctly or if the underlying surface is not prepared adequately.

If you’re considering using silicone render for your next construction project or are simply curious about its properties, keep reading. We’ll provide you with the information you need to make an informed decision and to ensure that your building stays crack-free for years to come.

What Causes Cracks in Silicone Render?

Although silicone render is known for its durability, it can still crack under certain conditions. Here are some of the factors that can cause cracks in silicone render:

Poor substrate preparation: If the substrate is not prepared correctly before the silicone render is applied, it can lead to cracking. The substrate should be clean, dry, and free from any loose material. Any defects, such as cracks or holes, should be repaired before the silicone render is applied.

Weather conditions: Extreme temperatures and weather conditions can cause silicone render to expand and contract, leading to cracks. This is why it’s essential to choose a high-quality silicone render that’s designed to withstand local climate conditions.

Incorrect application techniques: If the silicone render is not applied correctly, it can lead to cracking. It’s important to follow the manufacturer’s instructions and to use the correct tools and techniques for applying the render.

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ProGuard Exteriors are your first choice for quality local workmanship throughout the South East of England.

Call us today on 0800 612 5254 to arrange a free quote or get in touch for more information on how to protect and transform your home!

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Can Silicone Render Crack?

One of the most common questions about silicone render is whether or not it can crack. While silicone render is more flexible than traditional renders and less likely to crack, it is not completely immune to cracking. However, the likelihood of cracking can be significantly reduced by taking certain precautions during installation.

There are two main types of silicone render: thin coat and thick coat. Thin-coat silicone render is less likely to crack than thick-coat silicone render, as it is more flexible and less prone to shrinkage. However, thick coat silicone render can still be durable when installed correctly.

The lifespan of silicone render can vary depending on several factors, such as the installation’s quality and the maintenance level. Generally, silicone render can last for around 25 years, but it may require repairs or reapplication over time.

How to Prevent Cracks in Silicone Render

Silicone render is durable and long-lasting, but it can still crack if not applied correctly or maintained properly. Here are some best practices to prevent cracks in silicone render:

A. Best practices for preparing the substrate before application

  • Clean the substrate thoroughly to remove any dirt, debris, or loose material that may affect the adhesion of the render.
  • Ensure the substrate is dry before applying the render. If there is any moisture present, it can cause the render to crack or peel.
  • Apply a suitable primer to the substrate before applying the render. It helps to improve the adhesion of the render to the substrate and prevent cracks.

B. The proper techniques for applying silicone render

  • Use the correct tools and equipment to apply the render, such as a trowel or a rendering machine.
  • Apply the render in thin and even layers, following the manufacturer’s instructions.
  • Use the correct amount of water when mixing the render, as too much water can weaken the render and cause it to crack.
  • Allow the render to dry and cure properly before applying any additional coats or paint to the silicone.

C. How to maintain the render to prevent cracks

  • Regularly inspect the render for any signs of cracking or damage, and repair any issues as soon as possible.
  • Keep the surface of the render clean and free from dirt and debris, as this can affect the surface’s hydrophobic properties.
  • Avoid harsh chemicals or pressure washers on the render, as this can damage the surface and cause it to crack.
  • Apply a suitable protective coating to the render, such as a silicone-based sealer, to improve its durability and prevent cracking.
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How to Repair Cracks in Silicone Render

Fixing cracks in silicone render is a simple process that can be done by following these steps:

  1. Clean the affected area – use a wire brush or scraper to remove any loose material from the crack.
  2. Apply a primer – apply a silicone primer to the area surrounding the crack to help the silicone filler adhere.
  3. Fill the crack – using a silicone filler, fill it completely, ensuring it’s level with the surrounding surface.
  4. Smooth the surface – use a trowel to smooth the surface of the filled crack and ensure it blends in with the surrounding area.
  5. Allow the filler to dry – check the manufacturer’s instructions for the drying time of the filler.
  6. Sand the surface – once the filler is dry, use fine-grit sandpaper to smooth the surface and remove any rough edges.
  7. Apply a topcoat – apply a topcoat of silicone render to the repaired area, making sure to blend it in with the surrounding area.

Materials needed for the repair

  • Wire brush or scraper
  • Silicone primer
  • Silicone filler
  • Trowel
  • Fine-grit sandpaper
  • Silicone render for topcoat

Tips for ensuring a long-lasting repair

  • Ensure the surface is clean and dry before beginning the repair process.
  • Apply the primer evenly to the surrounding area to ensure the filler adheres properly.
  • Fill the crack completely to prevent future cracking.
  • Smooth the surface of the filler to ensure it blends in with the surrounding area.
  • Allow the filler to dry completely before sanding and applying a topcoat.
  • Apply the topcoat of silicone render evenly to ensure a seamless repair.

The Final Word: Keeping Your Silicone Render Crack-Free

Silicone render is an excellent choice for external building finishes due to its durability and resistance to weather and water. However, cracks can still occur, especially if the substrate is not properly prepared or if the application technique is incorrect. By following the best practices for preparing the substrate, applying the silicone render correctly, and maintaining the surface, you can prevent cracks from forming. If cracks do appear, the repair process is straightforward and can be done with a few basic materials. Remember to follow the manufacturer’s instructions for both the repair process and maintenance to ensure your silicone render remains crack-free for years to come.

does silicone render crack


Is it true that silicone render never cracks?

No, while silicone render is more resistant to cracking than traditional renders, it is not completely crack-proof. Factors such as substrate preparation, weather conditions, and application techniques can all impact the potential for cracking.

What are some common causes of cracks in silicone render?

Cracks in silicone render can occur due to a range of factors, including substrate movement, weathering, and poor workmanship during application.

Can different types of silicone renders have different cracking properties?

Yes, different types of silicone renders can have varying properties when it comes to cracking. Some may be more flexible and able to resist cracking, while others may be more prone to cracking under certain conditions.

How long can I expect my silicone render to last before it cracks?

The lifespan of silicone render can vary depending on a range of factors, including the quality of the product used, the quality of the substrate, and the application techniques used. In general, silicone render can last for around 25 years or more if applied correctly and maintained properly.

Can I repair cracks in the silicone render myself, or do I need to hire a professional?

It is possible to repair cracks in silicone render yourself if they are small and not too extensive. However, larger or more complex repairs may require the expertise of a professional. It’s important to ensure that any repairs are carried out correctly to prevent further damage to the render.

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ProGuard Exteriors Ltd is a highly rated external rendering and insulation company providing bespoke packages for homeowners, developers and businesses across South East England.