Accurate rendering of Gisoton bricks

GISOTON bricks are heat-insulating and mainly consist of a core of polystyrene and expanded clay on the front side. Different surfaces require a tailored choice of renders for the reliable rendering of such bricks. The rendering of ThermoSchall, WärmeDämmBlock, Gisoplan Therm GPT masonry and Gisoplan TTW masonry (partition walls) is described here below.

Plastering

Simple & safe to the goal

Case 1: Gisoplan Therm GPT / Outdoors

1. Before starting work, the substrate must be checked. Broken out and missing areas, eventual joints > 2 mm or untreated insulation boards must be pre-treated either with the PU filling foam weber.therm 345, a bonding and reinforcing mortar (weber.therm 300) or a lightweight underlay reinforcing mortar (weber.therm 376).
2. Apply the reinforcing mortar weber.therm 376 in a thickness of approx. 15 mm on the underlay render. Rule level flush and perpendicular with a straight edge (for ex. aluminium beam); if necessary, use a nail float (scraper).
3. Insert the glass-fiber mesh cloth weber.therm 310 full-surface in weber.therm 376. It must lay in the upper third of the reinforcing mortar layer and overlap the adjacent masonry by at least 30 cm.
4. Roughen the surface of the reinforcing mortar 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 stiffening.
5. Depending on the type of overlay render and weather conditions, the reinforcement layer must be eventually pre-wetted or pre-treated with the universal primer weber.prim 403.
6. After a sufficient waiting time of 1 day per mm thickness, apply and work to texture a thin-layer top render, like the mineral floated top render (with Jura grains) weber.star 220 on the reinforcement layer.
Case 2: Heat-insulating Block / Thermoschall

1. Before starting work, the substrate must be checked. Breakouts and defective areas, eventual joints > 5 mm or untreated insulation boards must be leveled out with a lightweight underlay render, e.g. weber.dur 132 or 137 / 137 SLK (fiber-reinforced).
2. Apply either weber.dur 132, weber.dur 137 /137 SLK or weber.dur 140 SLK (very lightweight and fiber-reinforced) in a thickness of 15-20 mm. Rule level the render flush and perpendicular with a straight edge (for ex. aluminium beam).
3. Directly embed the mesh cloth directly in areas with material transitions or in highly stressed areas. A full-surface reinforcement layer is usually not necessary. If such a full-surface layer is used, observe the recommended waiting time.
4. Depending on the type of overlay render and weather conditions, the reinforcement layer must be eventually pre-wetted or pre-treated with the universal primer weber.prim 403.
5. Apply a mineral overlay render, e.g. the lightweight mineral fine-grained top render weber.star 261 AquaBalance.
Case 3: Gisoplan-Block & Trennwand / Indoors

1. Indoors: GISOPLAN-Block and Trennwand (block walls and partition walls) can be plastered as follows, whenever the residual moisture content is ≤ 3 M%; the lime underlay plaster (base coat) weber.cal 174 is applied in a thickness of approx. 10-15 mm. Rule level flush and perpendicular with a straight edge (for ex. aluminium beam).
2. As the top coat render indoors comb the 1st layer; the next day apply a second layer weber.cal 174 in a thickness of 3-4 mm. After stiffening, the rule off to a flat and in-plane surface with a wooden float or to a smooth surface with a sponge or felt float.