Building services defects, which caused extremely high energy usage and a high rate of disruptions in all of the building services, were the reason for comprehensive retrofitting measures at the Kreishaus (district office) in Siegen. According to regional press coverage, the building services in the Kreishaus were last updated in the early 1970s. Leaking pipes and significant fire-safety hazards are just a few of the problems necessitating a renovation. The building consists of two sections; the side wing was built in 1953, and the addition was constructed in 1969.
In order to carry out the comprehensive retrofitting work, the two building sections – more than 60 meters tall and each up to 50 meters wide – were completely outfitted with scaffolding. The contract for the scaffolding work was granted to Afflerbach Gerüstbau GmbH & Co. KG, based in Kreuztal-Buschhütten, by Köster AG, the general contractor hired for the renovation project. The Afflerbach company has more than 40 years of scaffolding experience, and has worked with MJ-Gerüst GmbH in Plettenberg from the beginning. Afflerbach Gerüstbau GmbH & Co. KG has a scaffolding inventory comprising 150,000 square meters of framework scaffolding, including modular scaffolding, and employs 30 people. For the Kreishaus in Siegen, approx. 11,500 square meters of MJ UNI 70 as well as an MJ-compatible scaffolding system were used. In addition, there were 2,400 meters of interior ladder cages, 1,500 meters of aluminum paneling, 72 meters of heavy-duty lattice girders and 26.50 meters’ worth of walk-through frames for constructing a pedestrian tunnel. The aluminum panels were Load Class-4 aluminum framework panels. These were delivered exclusively by MJ-Gerüst GmbH and provide an enormous advantage because they are very easy to work with.
Two building projections posed particular challenges when it came to the scaffolding work. One of these projections is at a height of 40 meters on the side of the building with a 20-meter scaffolding structure built on top of it, and the other is on the street side at a height of 45 meters. Both are being managed with a heavy-duty lattice girder bridging and a pipe coupling structure, with the scaffolding structure built on top of each. On the side wing, the lattice girder bridging extends 30 meters out from the building, and on the street side it is 16.50 meters wide. The lattice girders extend into the interior and under the structural projection of the building. There, they are connected to a modular scaffolding structure using pipes and couplings. This allows the lattice girders to transfer the load from the lattice girder bridging to the modular scaffolding structure.
Another significant challenge for the scaffolding work was anchoring the scaffolding structure. Because the building’s façade is made up almost completely of windows, which prevented a conventional anchoring of the scaffolding structure, a specialized solution needed to be found to suit the building conditions. Accordingly, 25-cm-long drills were used to make 5.7-mm holes between the individual glass elements into the aluminum balcony railing supports behind the glass façade. “Self-tapping” screws measuring 6.3 mm across were inserted into these holes. The screws, manufactured by EJOT, have heads consisting of a 10-mm outer thread. Elastic rings were screwed onto the 10-mm threading of the GT screws, and were used to secure the scaffolding. This EJOT fastening system exerts a very high axial extraction force toward the scaffolding, which allowed the scaffolding structure to be anchored in this way across the entire façade of the building.
The various statics needed for these special requirements and conditions were provided by the Bochum-based Klimpel engineering office (contact: Michael Klimpel, Graduate Engineer). Klimpel is a member of the Technology technical committee of the Federal Scaffolding Guild, and specializes in unusual requirements for scaffolding. In addition, Henning Afflerbach created a hazard analysis for the scaffolding work at the Kreishaus in Siegen. The scaffolding project manager for this project is Mr. Henning Afflerbach, the managing partner of Afflerbach Gerüstbau GmbH & Co. KG.
The scaffolding is scheduled to be in place for 63 weeks, through the end of 2009. It was originally erected by four people over a period of 45 days. However, the extensive retrofitting work and the special conditions of the project mean that it must be rebuilt regularly during the construction phase. These modifications are overseen by Mr. Henning Afflerbach, the project manager and head of Afflerbau Gerüstbau GmbH & Co. KG.