Beads are highly recommended on lightweight substrates susceptible to movement, especially on the corners to achieve the desired aesthetics on the final finish. However, standard beads can still come away from the substrate when movement occurs, causing cracks on the finished surface. Using mesh beads is a great way to reduce the risk of cracking.
How mesh beads work
The risk of visible cracking due to substrate movement is reduced with the mesh in these beads creating a barrier between the substrate and base coat render, and the top coat render. The substrate hairline cracks only go as far as the mesh, while the render top coats remain without cracks.
Why does substrate movement occur?
Substrate movement can occur due to changes in the soil’s moisture content (i.e. from rainfall or extended dry heat periods, or vegetation roots soaking up moisture). Sometimes this movement causes structural cracking in substrates, which requires the attention of a building professional. Minor substrate movements triggered by these changes in soil moisture can lead to hairline cracks in render or cause standard beads to come away from the substrate.
Using mesh beads with acrylic renders
Acrylic renders provide additional flexibility, reducing the likelihood of visible hairline cracking. However, using mesh beads reduces this risk even further. But mesh may not prevent visible and larger structural cracks from appearing on surfaces.
Mesh can be applied to the entire substrate in the first layer of a suitable render to reduce the visibility of hairline cracking. Meshed beads ensure the same protection for the corners of the substrate. They also increase the adhesion of the render system to the substrate compared to standard beads.
Meshed beads are highly recommended for use on Natural Materials systems for interior projects, EPS substrate systems, and lightweight substrate systems (such as blueboard). Meshed beads can be used on both outer and inner corners of substrates.
Consult with Rockcote Enterprises on how to use meshed beads for your projects.