Restoring the Rainbow Tower

The original water tower dates back to 1964, seven years before the formation of the Studio Original Designers 6R5 Network (the Studio). In 1990 the Studio realized the Torre Arcobaleno as an extension of their experimental project Wonderline, which was influenced by the work and words of Pablo Picasso. Seeing color linked to emotions, the Studio approached the tower's new skin as a means of bringing creativity and life to a gray area, in order to stimulate the emotions of passersby.

Due to its location next to busy roads and railroad tracks, the tower was attacked by pollution and graffiti over the course of 25 years. Further, the iron structure inside the concave tower pushed outward to break some of the concrete substrate and pop out some of the ceramic tiles. These concerns led the Studio to return to Porto Garibaldi to clean and repair the Rainbow Tower in time for the Expo Milano 2015. 

Beyond the colorful exterior made up of 10x10 tiles in black, white and a dozen more colors, the most distictive aspect of the 35-meter-tall tower is its hourglass form. At its base the tower has a 12-meter diameter, while at the top its diameter is 10 meters; in between in tapers to a narrow diameter of 8 meters. With a total surface area of 1,000 square meters, 100,000 tiles were used to cover it from top to bottom. In 2015, as in 1990, the tiles were supplied by Marazzi: their Sistem C ceramic tiles. The biggest difference in the 25 years is the recycled content of their current tiles, which carry a LEED certification.

In addition to the Studio and Marazzi, the team on the refurbishment included Bazzea, Condor S.p.A., FILA Solutions, and MAPEI. Bazzea was in charge of the technical management of the construction site. They started by cleaning the ceramic surfaces, and then they went on to remove the graffiti that was defacing the surface, protecting it, and once the job was completed, using special anti-graffiti paint. Subsequently, they replaced the missing and damaged tiles, and repaired and painted the 24 35-meter-tall concrete ribs. Lastly, they covered the tower roof using a double waterproofing sheathing to better weatherproof the structure.

Condor oversaw the scaffolding, which needed to navigate the concave form of the round tower. They used Multicom, their multidirectional scaffolding that adapts to any complex surface. FILA Solutions carried out cleaning and protection of the external façade, using their Phzero concentrated acid descaler to remove dirt on the glazed ceramic tiles. FILA's Nopaint Star was used to remove the graffiti on the lower portions of the tower, and their Stop Dirt was applied at the end as an invisible dirt repellant and anti-graffiti protector.

Last but not least, MAPEI's work included the preparation of the surfaces by removing the tiles that had become detached, a thorough cleaning of all the surfaces, and the removal of crumbling areas. Their laundry list of products included Mapefer 1K and Planitop Rasa&Ripara for the repair work on the concrete ribs; Elastocolor Primer and Elastocolor Waterproof for painting the uprights; Ultralite S1 and Ultracolor Plus to bond and grout the new tiles; Mapesil LM to seal the joints.

All tolled, the renovation – paid for by the project’s partner companies and architects as a gift to Milan its visitors – employed 37 workers and was completed in just 71 days, in time for the Milano Expo 2015.