Direct-applied rendering to surfaces with a poor key
Renders are not adhesives and require a combination of suction (drawing of the most liquid elements into the substrate) and mechanical key (texture or roughness) to bond to its substrate.
Solution with the following Weber products
Preparatory key coat for rendering
One coat, through coloured monocouche render
Pre-blended single coat application renders
Silicone-based, through-coloured, decorative finish
Acrylic-based, composite, decorative finish