Facade Insulation. Durable And Safe

Facade insulation: The building shell of these apartment buildings complies with the requirements of KfW Standard 55. For the cladding made of sand-lime brick, the board of the housing association, in coordination with planners and construction companies, chose a thermal insulation system from Caparol with a rockwool core from Rockwool.

Photos: Deutsche Rockwool

"For years we have been relying on sustainable building materials for all new buildings, renovations and additions, which not only reduce the energy consumption of the buildings, but also cut a good figure in the recycling cycle," explains the technical board of the Märkische Scholle, Jochen Icken.

Exterior wall constructions for facade insulation

The facade insulation on the second building was completed in July 2019. "A construction step that is close to my heart," confirms Icken. He is a civil engineer himself and has gained experience at the Märkische Scholle in eleven years and made fundamental decisions.

“We know that fully mineral exterior wall constructions and a coating with silicone resin paints are long-lasting and help us to achieve ambitious savings goals in terms of energy costs,” he reports. "We can prove that with numbers." Robert Murjahn Institute in Ober-Ramstadt scientifically supported test with five similar buildings of the Märkische Scholle, in whose facade insulation sensors were installed, via which the mode of action of different insulation materials is analyzed in more detail. “Non-combustible stone wool insulation has been in place for a long time because we offer our members long-lasting and safe thermal insulation. But still we are looking forward to the measurement results, through which we learnwhat temperatures develop in a wall construction in the changing seasons and what influence this has on their durability."

Facade insulation

In order to achieve the desired U-value for the building shell of the seven apartment buildings in Lichterfelde, DWB installed 180 mm thick Coverrock II insulation boards on the recommendation of the manufacturers. The Coverrock II is a non-combustible plaster base made of stone wool with thermal conductivity 035. With its highly compressed top layer, it offers excellent plaster adhesion. The two-layer characteristics of the panels should ensure rapid construction progress. Thanks to this, the plates can be easily cut and pegged. The double-sided coating of the panel surfaces also enables mechanical processing of the adhesive mortar and plaster application without press filler, which saves a lot of time, especially on very large facade surfaces.

At the request of the structural engineer, the insulation boards in the current Märkische Scholle project are fastened with classic 60-mm dowels. The recessed dowels are each covered with a stone wool rondelle. This avoids thermal bridges that could later lead to visible discolouration of the surface coating.

Not flammable over all floors

Construction manager Ripolz and his colleagues are happy to accept the disadvantage of the slightly higher board weight of stone wool insulation. “When I work with lightweight polystyrene insulation, I have to use some mineral wool fire bars in multi-storey buildings like those here in Lichterfelde and, because of the clinker of the base, I have to cover the entire ground floor with a non-flammable class A1 insulation. The proper implementation of these legal requirements, especially in the case of buildings with staggered floors, is then regularly discussed lengthily between all those responsible. That is why it is only right for us if a building owner does not hesitate long and immediately decides on completely non-combustible facade insulation."

Mineral for a good climate

Board member Jochen Icken is convinced that the house residents not only benefit from a fully mineral outer wall construction in the event of a fire. “The issue of diffusion ability is also important. The members of the Märkische Scholle feel comfortable in their apartments and this has to do with our efforts to provide good sound insulation as well as with a good indoor climate and, of course, the high design quality of the entire system. Good living and living can be planned to a certain extent, I am firmly convinced of that."

Top up and gently compact

The Märkische Scholle has a total of around 3,700 apartments, in the Gartenstadt Lichterfelde Süd alone over 900 from the 1930s and 1960s. Since 2014, most of them have undergone extensive energetic and socially compatible renovation. The color concepts for the mineral-insulated facades were created in close coordination between the responsible architectural firm, Caparol and the board of the Märkische Scholle. "We have been working with Caparol for many years," explains Icken, "and the Märkische Scholle was one of the first housing companies to consistently switch to 'Thermosan NQG color." for longevity. Caparol consultant Michael Karst reports:“With all facade renovations of the Märkische Scholle, we coat twice with our best silicone resin paint on a colored plaster. In order to prevent premature algae growth and pollution, 'Thermosan' uses the high-quality binder technology nano-quartz lattice. This means that the color tones are color-stable much longer than with conventional silicone resin paints.”

Armed against harsh weather

An outer wall, fully mineral - from the brick to the insulation to the final coating - Jochen Icken is convinced that he has made the best choice for the members: “Extreme weather events such as excessive heat or heavy rain will be more and more common in the future and our buildings collapse. The new as well as the renovated buildings of the Märkische Scholle with their outer wall constructions are well prepared for this.”