The Weissenhof Estate in Stuttgart is an acknowledged part of the international history of architecture. The semi-detached houses at Rathenaustrasse 1 and 3 were designed by Le Corbusier and his cousin Pierre Jeanneret in 1927 on the occasion of the exhibition of the German Werkbund. Following the refurbishment work carried out in accordance with the preservation order by the Wüstenrot Foundation in 2003–2005, the Weissenhof Museum was opened here in October 2006, under the patronage of the Stuttgart city authorities.
Le Corbusier designed the semi-detached houses around a reinforced concrete frame, which supports the suspended floors and stairs, and allows ample design freedoms for the plan layout and facades. The rooftop garden, or rooftop terrace, which the architect himself called the “best place in the house”, is a key element in this Le Corbusier design. The rooftop garden is identical with the flat roof of the building and long-term waterproofing was essential for protection against moisture. The entire rooftop terrace plus the canopy and two stair shafts were waterproofed with KEMPEROL.
A liquid-applied waterproofing material was chosen because it adapts perfectly to every detail of the substrate. This permanently resilient waterproofing system accommodates structural movements and creates a full bond with the substrate so that moisture cannot sleep underneath. For reasons of appearance, no exposed sheet metal was allowed at junctions and upstands in the vicinity of the parapet. The specification required that the waterproofing be laid without additional fixings and such that all laps in the fleece remain invisible in order to guarantee the uniformity of the facade. In order to create the homogeneous look of a rendered surface, KEMPERDUR quartz sand was applied to the KEMPEROL waterproofing material with a spray gun while it was still wet.
This latest refurbishment project involved removing the entire terrace finishes dating from the first refurbishment project (1984) and returning the parapet to its original size, which was made possible by using a better-quality, thinner insulating material. The new plant containers, paving flags with the same dimensions as the originals and the differentiated colour scheme were adjusted to match the 1927 design. The original canopy, which forms the topmost part of the house, was completely replaced by a new concrete structure and likewise protected with KEMPEROL products.