Render beads might seem like a small detail, but they are vital in ensuring a smooth, durable finish on rendered surfaces. These thin strips, typically made of PVC or metal, provide structure and protection to the render, preventing cracks and wear in key areas. In this blog, we’ll explain why render beads are essential for a professional, long-lasting render system and how they contribute to the overall quality of your property’s façade.

Types of render beads and their uses

1. Corner Beads
   Corner beads are installed on the external corners of walls to create sharp, defined edges. They help protect corners from impact damage and ensure a clean, professional finish.
2. Stop Beads
   These beads are used to create a clear, defined stop point where the render finishes, such as around doors, windows, or between different materials. This ensures the render doesn’t spread beyond its intended area.
3. Bellcast Beads (Drip Beads)
   Bellcast beads are placed at the base of walls to direct rainwater away from the rendered surface. This prevents water from seeping into the render, protecting against moisture damage and helping maintain the integrity of the façade.
4. Movement Beads
   Movement beads are essential on larger surfaces where there’s likely to be thermal expansion or contraction. These beads absorb the movement in the render, preventing cracks and ensuring the render stays intact.
5. Expansion Beads
   Expansion beads are designed to allow for movement in the substrate or building structure. They are typically used on long, continuous walls or where different materials meet, preventing the render from cracking under stress.
6. Window Head and Reveal Beads
   These beads are used around window heads and reveals to create clean, precise lines and protect the edges from cracking. They also help seal and finish areas around windows, preventing moisture from entering these vulnerable points.
7. Arch Beads
   Arch beads are specifically designed for use around curved or arched areas. They help create smooth, defined edges, make rendering complex architectural features easier, and ensure an even, professional finish.

Benefits of render beads

1. Crack Prevention
   One of the biggest concerns in rendering is cracking. Render beads, especially expansion beads, are designed to absorb movement and stress in the render. This is essential for preventing cracks from appearing, especially in areas prone to thermal expansion or in older properties where movement is more likely.
2. Enhanced Durability
   Render beads protect the most vulnerable areas of your façade, such as corners and edges. Without proper protection, these areas are prone to chipping and wear, which can lead to further damage. By reinforcing these zones, render beads increase the overall durability of the render, ensuring it stands the test of time.
3. Improved Aesthetic
   For a crisp, professional finish, render beads are a must. Whether creating a straight edge around a window or a smooth finish on a corner, these beads ensure that the rendered surface looks flawless. Without them, achieving a clean, defined result is much more difficult, especially around complex details.
4. Weatherproofing
   Bellcast beads are particularly important in the UK’s unpredictable weather. Directing rainwater away from the rendered surface reduces the risk of moisture infiltration, which can lead to issues like cracking, dampness, and mould growth. Effective weatherproofing is critical to the long-term performance of any render system.
5. Cost Efficiency
   While render beads add a small cost to your project upfront, they can save you significant money in the long run by preventing damage, cracking, and the need for frequent maintenance. A properly reinforced render system will last much longer and require fewer repairs.

Embedding beads in the EWI system

Embedding render beads into the basecoat layer is essential for achieving a durable and professional finish. Start by preparing the surface, ensuring it is clean and debris-free for proper adhesion. The surface will often be the insulation, so ensure it is rasped in the case of EPS. Rasping creates a mechanical key for better basecoat adhesion.

Next, measure and cut the render beads to the required length, then apply a 3-6mm thick layer of basecoat render to the surface using a trowel. Position the render bead into the wet basecoat, carefully aligning it along corners, edges, or joints, and use a spirit level to ensure it’s straight. Press the bead into the basecoat, embed the mesh wings fully, and smooth out any excess material.

If necessary, apply a second basecoat layer over the bead’s mesh for additional strength. Allow the basecoat to set fully, ensuring the beads are secure, before applying the final render layer. Once set, apply the final coat smoothly over the beads, ensuring seamless integration for a professional finish that offers structural support, prevents cracks, and creates clean, defined edges.