Professional rendering/plastering of polystyrene formwork blocks

Depending on the surface's unevenness, polystyrene formworks blocks can be rendered/plastered after filling either with a normal reinforcing mortar or a special lightweight render. Both coated and uncoated formwork blocks are suitable for this purpose. Observe the prevailing guidelines and approvals of the stone manufacturers.

Simple & safe to the goal

  1. Application

    1. Clean the polystyrene formwork blocks thoroughly. Fill joints up to max. 1 cm with foam prior to rendering/plastering works. In case of unevenness > 7 mm, it is recommended to use the lightweight underlay reinforcing mortar weber.therm 376; in other cases, use the bonding and reinforcing mortar weber.therm 300.


    2. Place the ultra-solid mesh for corner reinforcement weber.therm 312 on all corners, for ex. soffits and lintels (in the same way as for all weber.therm ETICS).


    3. Afterwards insert the woven mesh weber.therm 310 "wet-in-wet" full surface. In case of openings, use a diagonal reinforcing mesh in the corners.