Exterior wall construction allows building in winter
New senior residence in an idyllic wine town
A modern senior residence was built in Lauda-Königshofen, in the northeast of Baden-Württemberg, during the winter of 2022/23. The new "Haus Tauberblick" offers 51 residential units for assisted living, spaces for a larger shared living community, and room for 40 day care guests, all within a usable area of approximately 5,500 square metres. The exterior walls were largely constructed using a timber frame. The advantages of prefabricating the exterior wall elements in the workshop of Aeckerle-Holzbau GmbH were complemented by an innovative cladding solution that enabled assembly on site even in adverse winter weather conditions.
The new "Haus Tauberblick" offers 51 residential units for assisted living, as well as communal spaces and room for 40 day care guests. The exterior walls were constructed using a timber frame.
At the start of the construction work, the basement was partially built and the ground floor was erected using solid construction methods. The latter was insulated using 160 mm-thick weber.therm A200 mineral wool lamellas. The load-bearing walls of the three upper floors were constructed using cross-laminated timber.
"We prefabricated all the timber-frame parts for the non-load-bearing exterior walls in our workshop and then assembled them promptly on site", explains Andreas Hunnecke, Dipl.-Ing. (FH) and fire protection engineer at Aeckerle-Holzbau GmbH, which was not only responsible for all carpentry work but also acted as the general contractor, taking significant responsibility for developing the fire protection concept.
The non-load-bearing exterior walls of the new senior residence are based on a 240 mm stud frame, insulated with non-combustible stone wool. The interior is lined with 15 mm OSB boards and 15 mm-thick Rigidur H gypsum fibreboards. Where necessary, an additional facing shell was added to accommodate required installations. The exterior lining was completed using the moisture-resistant Rigips Glasroc X special gypsum board.
Non-combustible lining was required
"The "Haus Tauberblick" is a building of Building Class 4. In addition to the non-combustible insulation layer, the fire protection expert involved also required a non-combustible exterior lining. This, among other factors, led us to Rigips Glasroc X — a moisture-resistant board from drywall specialist Rigips, which is particularly suitable for lining exterior ceilings and walls in timber construction", says Andreas Hunnecke. The exterior walls of the new senior residence are based on a 240 mm stud frame insulated with non-combustible stone wool. The interior lining comprises 15 mm OSB boards and a 15 mm-thick layer of robust Rigidur H gypsum fibreboards. Where necessary, an additional facing shell was added for required installations. The exterior lining was entirely made with Rigips Glasroc X boards, which are comparatively light, making them easier to handle during prefabrication. Additionally, they could be cut like regular hard gypsum boards by simply scoring them with a standard blade knife and breaking them cleanly.
According to the fire protection concept, fire resistance class F30-B was required for the exterior walls in Lauda-Königshofen. The implemented construction achieves F90-B on the outside and F30-B on the inside, among other things through the use of non-combustible Rigips Glasroc X (Euroclass A1).
Three months of guaranteed weather resistance
The Rigips Glasroc X boards can be used as load-bearing and bracing lining in timber construction according to ETA-21/0179. In addition to the static parameters, the document also includes information on the weather resistance of Rigips Glasroc X. For the exterior walls in Lauda-Königshofen, a fire resistance class of F30-B was required according to the fire protection concept. The ultimately implemented construction achieves F90-B on the outside and F30-B on the inside, among other things through the use of non-combustible Glasroc X (Euroclass A1).
"Another crucial property of the boards was their weather resistance: the exterior wall work was scheduled for October and November 2022, when weather conditions are highly unpredictable. Therefore, the unplastered exterior walls required temporary weather resistance to allow maximum flexibility for the trades involved. Thanks to their high moisture resistance, Rigips Glasroc X boards were developed specifically for this application. We sealed the joints immediately after assembling the wall elements using the corresponding Rigips Glasroc X joint tape, ensuring the required weather resistance of up to three months right away."
The exterior wall work was scheduled for October and November 2022, when the weather is typically unstable. Therefore, it was important that the unplastered exterior walls were temporarily weatherproof to ensure maximum flexibility for the trades involved. Thanks to their high moisture resistance, the Rigips Glasroc X boards were specifically developed for this application. The joints were sealed immediately after the wall elements were assembled using the corresponding Rigips Glasroc X joint tape, providing the required weather resistance of up to six months right away.
The connection to the load-bearing walls in cross-laminated timber solid construction was also carried out without any problems.
Hydrophilic silicone resin topcoat with decorative grain-on-grain structure
In subsequent work steps, the special boards from RIGIPS, which can be plastered directly, were fitted with a base coat weber.therm 300, a reinforcement mesh weber.therm 310 and a hydrophilic silicone resin topcoat weber.pas AquaBalance 481. This topcoat is particularly weather-resistant and does not require biocidal film preservation. It also allows for the creation of a decorative grain-on-grain structure. "In the transition areas from the timber construction to the solid ground floor construction, some details were still to be finalised. These were resolved in collaboration with the responsible plasterer and the Saint-Gobain Weber application technician."
For Aeckerle-Holzbau GmbH, using Rigips Glasroc X was a "premiere" that could lead to further applications. "Thanks to its fire protection properties, ease of use and weather resistance, Glasroc X is a particularly interesting alternative to other board materials in timber construction", concludes Andreas Hunnecke.
The new senior residence "Haus Tauberblick." Photos: Marc Wiegelmann / SAINT-GOBAIN RIGIPS GmbH
Construction Details:
Client: U1Solutions GmbH, Heidelberg
Carpentry Work/General Contractor: Aeckerle-Holzbau GmbH, Lauda-Königshofen
Rigips Technician: Claas Loskamp
Weber Application Technician: Uwe Renner