Building regulations outlined by NHBC and LABC only advocate the use of austenitic stainless steel or PVCu beads in all external rendering applications, anywhere in the UK. Galvanised steel beads are no longer approved for external rendering in any situation.
Simpson Strong-Tie Sales Director Jon Head explains: “We only recommend the use of stainless steel or PVCu products for external applications. Galvanised steel beads should not be used externally, unless secondary protection against corrosion is provided.
Although it’s generally known for its corrosion-resistant properties, galvanised steel can react with the chemical components in render, which will lead to quality issues, from unsightly rust stains, to the degradation of the bead and possible cracking in the render.
Simply put, galvanised steel in external rendering may rust, which will reduce the lifespan of your work and can be costly to put right. But the good news is it’s easily avoided.
Stainless steel beads are specifically designed for cement based renders, and our range of stainless steel angle beads, bellcast beads, stop beads and movement beads, and the PVCu plastic alternative has been engineered to provide reinforcement and resist impact damage. Our range of beads makes bellcasts, corners, stops and abutments all easier to form, and they can be cut to size as required.”
For rendering and plastering made simple, download the Simpson Strong-Tie 2020 catalogue which is packed with handy tips and installation guidance… and make sure you stay away from Rusty!
For further information or to download our 2020 catalogue, visit www.strongtie.co.uk.