What do the former second largest building in Europe and a hotel by Robert de Niro have in common? The design with concrete! On the facade of one building and in the interior of the other, this material plays a striking role. - Exposed concrete once had a bad reputation, but today it is impossible to imagine the world without it. Its natural grey colour conveys a certain elegance and timelessness, but it can also be coloured.
- Marcin Stępniewski-Janowski
- Likus family, Krakow
- Radoslaw Galczynski
Oldest skyscraper repaired
It can already be seen from a distance of more than 20 kilometres: The Warszawa Hotel in Poland's capital Warsaw. The building with its 16 storeys and a height of 66 metres was built between 1931 and 1933 and was considered the tallest building in Poland and the second tallest in Europe at that time. Originally, it served as the headquarters of the English insurance company Prudential and thus fulfilled its purpose as an office building in the centre of Warsaw. The building was built in steel skeleton construction and designed in the Art Deco style. After the war, only the steel frame and structural elements made of concrete in the lower section were still standing; the rest of the building fabric had been destroyed. After its reconstruction in the early 1950s, the building served as a hotel from 1954 to 2002, after which it remained unused for a long time until a hotelier family from Krakow had it renovated and reopened it as the luxurious five-star Hotel Warszawa at the end of 2018. Even today, the building has 16 floors and two basement levels, which house the restaurant and bar, café and spa area. The remaining floors contain 142 individually furnished luxury rooms and flats.
Historic concrete put into the spotlight
The interior of the hotel is dominated by materials such as concrete, wood, natural stone, copper and glass. They can be found throughout the lobby, in the rooms, in the spa area and in the restaurant. During the renovation, craftsmen uncovered concrete foundations and the managers decided to turn them into a design accent.
"On the ceilings there are historical construction elements made of concrete, which are deliberately shown as a design element. It was important to the investor to present above all these historical concrete elements from the construction period. This also includes the basement area, where the historic concrete constructions can also be seen in the hotel restaurant. They are deliberately combined here with other, warmer-looking materials, such as wood or copper. The architects supplemented the historical concrete elements on the ceilings in part on the walls with new concrete imitations, which were designed with the help of a concrete fine filler," reports graduate restorer Dorothea Smatloch-Klechowska, who worked out the technologies used and also advised on the colour design of the wall and ceiling areas.
"Among the biggest challenges were also the cracking in the plaster, which probably occurred because the plasters in the interior set too quickly, and the creation of a colour concept that had to be neutral and, above all, the retouching of the historic concrete elements, which were not allowed to look new under any circumstances," the restorer recalls.
Deficiencies compensated - expression gained
The historic structural elements made of concrete date from the time of construction, i.e. the 1930s. "In keeping with the history of the building, the concrete was in poor condition: either the concrete surfaces were plastered or heavily soiled by the war," explains Smatloch-Klechowska. After uncovering and cleaning the concrete and having it retouched by an artist, those responsible decided to use KEIM Concretal-Lasur for the concrete areas in the basements. This KEIMFARBEN coating is applied semi-transparently over the concrete surface and can thus compensate for visual defects. In general, mineral glazes on concrete appear much more natural than plastic coatings because they do not overlay the natural concrete structure. KEIM Concretal-Lasur emphasises and preserves the character of the material.
Uniform surface structure
On the upper floors, there were a number of cracks on the walls. On the scratched plastered surfaces, the craftsmen applied KEIM Intact, a slurry and levelling coating for inhomogeneous substrates, which fills the cracks and makes the surface texture even. This was followed by painting with KEIM Innotop sol-silicate paint. Selected plaster surfaces in the rooms received a partial coat of KEIM Restauro-Lasur.
All walls and ceilings as well as concrete building elements in the interior were finished with products from the KEIM range. "The investor has been using KEIM products for all his hotels and buildings for years and is convinced of their properties," knows Dorothea Smatloch-Klechowska.