Hotel Gradonna Mountain Resort “Kals am Großglockner”

Year: 2011-2012

Location: Kals am Großglockner

Country: Austria

Volume: 1.600 m³ expanded clay 1-16 mm

Owner Builder: Heinz Schultz

Contractor: Frey, Lienz- A/ Podesser-Bau, Ainet- A

Designer: ARGE Reitter/ Innsbruck- A

Problem / Solution

This location belongs to the most beautiful country sites of Austria, situated next to the highest mountain in the Austrian alps, the “Grossglockner”. Therefore it is easy to imagine the main problems like uneven underground, extreme weather conditions and conditions of delivery. Because of altitude both can change very rapidly and deep temperatures are also the reason for the required thermal insulation features of the expanded clay. Round about half a meter was the height of the layer under the foundation of the hotel. The material was delivered by trucks and poured out directly on the prepared ground.This facilitated a rapid progress in construction.


Directly on the surface a geotextile was unfolded. Then expanded clay was poured out of the truck and spread by an excavator. After levelling, a layer of concrete was put on top to build a plane surface for the reinforcement of constructing the foundation.

Why expanded clay?

The main requirements were stability and thermal insulation but resistance against chemical attack, frost resistance, no flammability where also decisive arguments to use expanded clay. A bulk density of 450 kg/m³ with a high stability, less necessity of compacting and not to forget- the environmental advantages.