Smart

Expansion

The Adel­indis Therme in Bad Buchau, located on the shores of Lake Federsee, offers guests a wide range of thermal and sauna expe­ri­ences across appro­xi­m­ately 14,000 m². Eight pools with varying tempe­ra­tures, bubble loun­gers, massage jets, and other well­ness features invite visi­tors to relax and unwind. Toge­ther with nearby clinics and a spa hotel, the Therme forms part of the Federsee Health Centre. The high quality of its offe­rings has earned the faci­lity multiple awards.

To create addi­tional space for well­ness and guest comfort, the operator – Moor-Heilbad Buchau gGmbH – commis­sioned the cons­truc­tion of a spacious exten­sion. In addi­tion to a new thermal pool, the project added a barrier-free entrance area with views of the Federsee land­scape, modern cashier and chan­ging areas, rela­xa­tion zones, a bistro, and a rooftop terrace featuring a sauna, pool, and garden.

The instal­la­tion of appro­xi­m­ately 3,500 m² of floo­ring across the extension’s three levels was carried out by Reiser GmbH from Bad Saulgau. The plan­ning and execu­tion of the tech­ni­cally deman­ding surface and drai­nage systems were closely coor­di­nated with system part­ners Ardex and Gutjahr.

Waterproofing

As part of the recent expan­sion of the Adel­indis Therme, a new, high-quality entrance and cashier area was created—designed to meet both archi­tec­tural and func­tional demands. Large-format tiles with a natural stone look provide a premium appearance and create a warm, welco­ming atmo­sphere throug­hout the exten­sion. The water­pro­ofing and adhe­sives were supplied by ARDEX.

To ensure long-term water­tight perfor­mance, the substrate was first treated with a self-leve­ling water­pro­ofing layer (ARDEX S 8 FLOW). The tiles were then laid using flexible adhe­sives (ARDEX X 78 and ARDEX X 90) speci­fi­cally desi­gned for the safe instal­la­tion of large-format surfaces. A rapid-setting flexible grout (ARDEX G 9 S FLEX 2–15) was used to achieve clean, even joints ranging from 2 to 15 mm in width.

A standout archi­tec­tural feature is the roughly 30-meter-long, four-meter-high wall in the entrance area. Clad in timber elements and illu­mi­nated by natural light, it makes a striking visual impres­sion.

The chan­ging areas posed a parti­cular tech­nical chall­enge. Nume­rous cut-outs had to be made to accom­mo­date 30 to 40 cm-high base units, which serve as static foun­da­tions for the lockers. These required a reliable decou­pling solu­tion to prevent cracking in the screed. A high-perfor­mance bonded uncou­pling mat (IndorTec VA FLEXBONE-VA) by GUTJAHR, speci­ally desi­gned for large-format tile instal­la­tions, was used to absorb struc­tural move­ment from the substrate. In combi­na­tion with a compa­tible bonded water­pro­ofing system, this resulted in a tech­ni­cally sound solu­tion that met both aesthetic and func­tional requi­re­ments.

Rooftop Terrace

The rooftop terrace—featuring a sauna, pool, and roof garden—required parti­cu­larly well-engi­neered tech­nical solu­tions. A perfect oppor­tu­nity for GUTJAHR to demons­trate its full exte­rior exper­tise, both in terms of drai­nage and year-round safety for users. In the outdoor sauna area, a heated floo­ring system was installed to prevent ice forma­tion in winter and to ensure slip-resistant walk­ways at all times.

This was achieved using a warm-water under­floor heating system, with pipes embedded in appro­xi­m­ately 20 cm of water-permeable drai­nage mortar. Reliable drai­nage is ensured by a two-level system: surface water is chan­neled through slim slot drains (Aqua­Drain SR) and a flexible grating system (Aqua­Drain FLEX). Below that, a specia­lized drai­nage mat—developed speci­fi­cally for use under exte­rior tile cove­rings on drai­nage mortar—forms the second drai­nage layer. With its capil­lary passive design, the mat effec­tively prevents stan­ding water from rising back into the tile assembly—an essen­tial factor in avoi­ding frost damage and efflo­re­s­cence.

The raised instal­la­tion of the tile surface over the open drai­nage struc­ture creates gene­rous drai­nage chan­nels, allo­wing water to flow away quickly and safely. The ceramic surfaces in wood and natural stone aesthe­tics offer both visual variety and high func­tion­a­lity. Barrier-free tran­si­tions were imple­mented in compli­ance with regu­la­tions using drai­nage grates that safely divert water into the under­lying drai­nage system without causing back­flow.

The combi­na­tion of water-permeable cons­truc­tion, varied slope condi­tions, inte­grated under­floor heating, and the use of precast concrete elements presented a considerable tech­nical chall­enge. However, the selected system design meets all the requi­re­ments for dura­bi­lity, drai­nage perfor­mance, and frost resis­tance.

Conclusion

All work was completed on sche­dule and without time cons­traints. Throug­hout the entire project dura­tion, the cons­truc­tion process—despite complex tech­nical requirements—was effi­ci­ently coor­di­nated thanks to close colla­bo­ra­tion among the involved compa­nies.

The expanded Adel­indis Therme now stands as a modern well­ness faci­lity that combines tech­nical precision with archi­tec­tural quality. Carefully matched complete systems for water­pro­ofing, decou­pling, and drai­nage ensure durable, high-perfor­mance surfaces—visually under­stated, func­tion­ally impres­sive. Visi­tors enjoy a relaxed, feel-good atmo­sphere, while a thoughtfully engi­neered floor struc­ture behind the scenes guaran­tees safety, acces­si­bi­lity, and comfort.

The design draws on regional refe­rences and blends harmo­niously into the natural land­scape of the Federsee moor. This project combines forward-looking tech­no­logy with context-sensi­tive architecture—resulting in a faci­lity built to inspire and perform for years to come.