Amberg’s “princely pool”
The “Kurfürstenbad” in Amberg is a popular swimming pool and leisure centre for the entire Upper Palatinate district of Bavaria – its architecture and concept make it a true gem. With diverse fun pools and a unique transparent membrane roof that lets plenty of daylight into the interior, it caused quite a sensation and attracted great interest when it opened back in 1990. In order to secure a continuous stream of visitors in the future, the facility has been extended by adding generous, attractive sauna and wellness zones plus a therapy area. The key issue was the need for reliable waterproofing and ceramic finishes on approx. 1,400 m² of floor and 500 m² of wall surfaces.
The waterproofing of buildings is an absolutely critical issue. Waterproofing should be designed “to last a lifetime” because subsequent corrections often entail huge amounts of costly work. In order to reliably waterproof the floor surfaces in these very heavily used areas against seepage of run-off water, the flooring contractor opted for a particularly high-quality floor construction.
First of all, a screed was laid on top of the concrete ground slab, with integral falls to match up with the outlets already in place. All floor surfaces were then given a coat of ARDEX BM-P rubber/bitumen primer before being fully waterproofed with cold-applied self-adhesive ARDEX BM polymer-modified bitumen flexible sheeting, which features the ability to bridge over any cracks. Due to its good “extensibility”, the highly elastic, especially tear-resistant ARDEX BM material guarantees dependable, long-lasting waterproofing even with the dynamic loads associated with new foundations. In addition, the rolls of waterproofing material are easily and quickly laid, and retain their excellent adhesive properties even at low temperatures. ARDEX BM-T self-adhesive elastic sealing tape was used for details such as floor/wall junctions or pipe penetrations.
Specific sequence of operations
For design reasons, the pipes for the underfloor heating were not laid until the floors had been completely waterproofed. The individual pipes were attached to the floor with elastic sealing tape before installing a layer of Styrodur insulation, which is not affected by moisture.
The next step was to lay a 5–6 cm thick heated screed, followed by the second waterproofing layer over the entire floor surface. Afterwards, large-format (50 x 50 cm) porcelain stoneware tiles were laid in ARDEX X 78 MICROTEC premium pourable thin set mortar. The special raw materials and coated fibres in this adhesive ensure that all tiles are fixed securely.
Finally, the wall surfaces were waterproofed with ARDEX S 7 flexible waterproof coating or ARDEX S 1-K one-component waterproofing compound depending on the loading class. After that, the large-format (30 x 60 cm) porcelain stoneware tiles were attached with ARDEX X 77 MICROTEC flexible floor and wall tile adhesive.