Rendering of lightweight concrete stones (pumice, KLB, Liapor…) and brickwork (normal-porosity substrates)
Normally absorbent substrates, such as pumice or brick do not require any pre-treatment of the substrate when applying the base coat (underlay render). In case of special measures in case of structural problems: refer to the page dedicated to lightweight perforated bricks.
Simple & safe to the goal
3. Leave the surface of the underlay to render (base coat) as required for the specific overlay render (top coat); in case of post-applied scratch renders, use a hard broom or a notched large trowel after first stiffening. In case of openings, the embedment of a diagonal meshcloth like weber.therm 310 (woven mesh) cut to size or weber.therm 315 (arrow-shaped glass-fiber mesh) for reinforcing the angles is recommended.