Kaifu-Bad – Historical baths saved by wood

Prefabricated elements combine traditional design and modern construction

Published: 14/04/2016 04:50

​​​The oldest swimming pool complex in Hamburg, Kaifu-Bad, is a protected monument originally constructed in 1895. It was closed for many years because the roof was in danger of collapsing. The renovation project posed multiple challenges: the need to respect the protected design, tolerate salt water and high humidity, and meet modern sustainability standards. All this could not be met with conventional means or steel structures. The solution was found in pre-fabricated wooden elements by Metsä Wood.

Kaifu-Bad - Wood offers every advantage against humidity and corrosion 

Wood offers every advantage against humidity and corrosion

As part of the renovation project, one of the pools was converted into a unique salt water bath. “What sounds simple presents unusual challenges for architects,” reports Manfred Voss, from the renowned architecture firm MRLV. “The salt water has a salt content of 6%, which is good for humans but bad for steel. The salt will consequently create an enormous exposure to corrosion. We knew from the beginning that a standard solution wasn’t an option.”

The old, ailing roof trusses needed to be replaced with a steel-free construction. The architect collaborated with structural engineer Stefan Heidrich from WTM Engineers. The whole renovation was done without metal joints. Wood was chosen as the primary material as it was the only way to handle both the big changes in temperature and the corrosive effects of high humidity, salt water and chlorinated water. “Using industrially manufactured, dimensionally stable Kerto-Q LVL wooden trusses helped us to achieve an efficient solution. We were able to develop an object-specific design that meets both the static and the economic requirements”, Voss continues.

Structural drawing of Kaifu-bad wood structures 

Pre-fabrication saves time and money

Constructing such a special kind of roof using engineered wood products, a high degree of pre-fabrication and plenty of joints without metal is a new approach in Germany. Due to the use of Kerto® LVL (Laminated Veneer Lumber) elements, the project also succeeded economically: As all the wooden parts were industrially manufactured, they were ready to install on site, which meant significant savings in construction time. The savings from the faster installation covered the extra costs of the challenging structure and moisture-proofing.

Versatility of Kerto preserves barrel shaped vaults

Pre-fabricated Kerto® LVL wood elements 

In the Kaifu-Bad renovation the Kerto products were used in a range of very different applications – from beams to panels. Kerto structures proved to be a very strong and dimensionally stable solution; one capable of carrying even large loads. For example, despite the 14-metre-long span, the main trusses could be manufactured in a thickness of only 134 mm. The 69-millimetre-thick Kerto-Q LVL panels used for the roof shell not only acted as panels but also stiffened the roof structures and stabilized the original brick walls against wind loads. In addition, the Kerto-Q panels allowed an arched cut of the bottom of the trusses, which preserved the historical barrel shaped vault.

The success of the Kaifu-Bad renovation was a result of a professional, service-oriented collaboration between the supplier, the designer and the builder.

Read the full story and experience the entire reconstruction of the historically valuable Kaifu-Bad.

For more information, please contact:

Henni Rousu, Marketing Manager, Metsä Wood,
mobile: +358 (0) 40 5548388, henni.rousu[at]metsagroup.com.