Application of smooth plasters

Smooth plasters can be applied both on basecoats and on external thermal insulation composite systems and also on insulating plasters. The norm DIN 18550 Part 2 generally states: "In the case of finely rilled, smooth or floated plasters, there is a risk of binder accumulation on the plaster surface during texturing, which promotes the formation of shrinkage cracks and, in the case of slaked lime mortars, inhibits the hardening of deeper layers". As a rule, coarser plaster structures should be used in exterior areas, as hairline cracking can never be ruled out with smooth ones.

Simple & safe to the goal

On underlay render (base coat)

1. Apply a lightweight render, e.g. the lightweight lime-cement underlay render weber.dur 132. Leave its surface as required for the specific overlay render (top coat). Waiting time > 14 days. For better stability, we recommend applying a full-surface reinforcement layer.
On ETICS

2. A double reinforcement layer of a suitable weber.therm bonding and reinforcing mortar + reinforcement fabric is applied on the chosen external thermal insulation composite system. A standing time of at least 7 days must be observed between these two reinforcement layers.
On insulating render

3. n top of the high-performance insulating render weber.therm 505 HDP apply a full-surface reinforcement layer consisting of the bonding and reinforcing mortar weber.therm 300 + reinforcement fabric.
On ETICS

4. A full-surface reinforcement layer of bonding and reinforcing mortar + reinforcement fabric is applied onto the lightweight underlay render (base coat) and the insulating render. After a standing time of at least 7 days the ETICS receives a second reinforcement layer, which again consists of the same bonding and reinforcing mortar + reinforcement fabric.
5. Apply the overlay render, e.g. the lightweight mineral fine-grained top coat weber.star 261 AquaBalance in a thickness of approx. 3 mm and work to the individual texture by smoothing the fresh render.
6. After an adequate waiting time, the silicate equalizing paint weber.ton 414 AquaBalance (if necessary, in 2 coats) is applied.