Media Release

Historic São Paulo Center Renovated and Protected with Penetron Waterproofing Technology


The first of two phases of construction of the renewed Cidade Matarazzo in São Paulo, Brazil, was completed in January 2023. The historic multi-use complex required an extensive renovation effort and includes a 15-floor hotel tower – and will be completed in a second phase within the coming 12 months. PENETRON ADMIX, a crystalline concrete waterproofing admixture, and PENESEAL PRO, a spray-on liquid sealer, were used to protect the below-grade concrete structures from high groundwater levels.

The Cidade Matarazzo is a newly renovated historic complex of 10 buildings in the center of São Paulo, Brazil. The $472 million (almost 3 billion reals) Rosewood São Paulo project covers 30,000 m2 and offers 160 guestrooms, 100 Rosewood Residences housed in the restored Matarazzo Maternity building (first built in 1943) and a new 15-floor Mata Atlântica Tower designed by Pritzker Prize-winning architect, Jean Nouvel. In addition, the complex comprises the Chapel of Santa Luzia, newly restored to its original 1922 state and open for weddings and other events, a culture center, a fashion retail center, and 34 gastronomy sites, including a rooftop pool and bar with views of the city. Further amenities include two swimming pools, a cinema, music studio, event space, and a wellness spa. In addition, an extensive art collection with more than 450 works by 57 contemporary Brazilian artists decorates the interior and verdant gardens.

“The Cidade Matarazzo project began as a massive renovation project to restore almost a dozen buildings protected as historical heritage,” recounts Cláudio Neves Ourives, CEO and Managing Partner of Penetron Brazil.

The initial phase of the project, repairing and securing the below-grade structures of the older buildings, required a methodical approach to identify, prepare, and repair damaged concrete support structures in the basements. Often, this meant drilling through basement walls for access. The depth of the excavations and repairs demanded the application of a reliable waterproofing product.

“Due to the success of our many other concrete repair projects across the country, the project developer and the project consultants specified the Penetron System, in particular, PENESEAL PRO to ensure waterproofing protection for the existing below-grade concrete slabs of the Mata Atlântica Tower,” adds Cláudio Neves Ourives. “Construction plans also specified PENETRON ADMIX, an integral crystalline concrete waterproofing solution for both the reconstruction of existing concrete elements and the construction of the new concrete structures of the other buildings.”

PENESEAL PRO is a spray-on liquid sealer that forms a barrier to seal hairline cracks and protect concrete against water penetration. Once applied, it creates a sub-surface gel that seals the pores, capillaries and cracks – and remains active as long as water is present, sealing any future hairline cracks.

Easily mixed in during batching, PENETRON ADMIX was used to treat the concrete for the foundation slabs and retaining walls during the second phase of construction, now ongoing. PENETRON, a topical crystalline waterproofing material, and PENECRETE MORTAR, a crystalline waterproofing repair grout, were used in combination to repair and waterproof the existing concrete structures of the Matarazzo Maternity and other historic buildings. PENEBAR SW, a swellable waterstop, was applied to seal the construction joints of the below-grade structures.

Once added to the mix, the active ingredients in PENETRON ADMIX generate a non-soluble crystalline formation throughout the pores and capillary tracts of the concrete that permanently seals microcracks, pores and capillaries against the penetration of water or liquids from any direction. This formation provides long-term protection for concrete from deterioration, even under the moist environmental conditions found at the construction site.

“The Penetron System performs consistently during the service life of the concrete. The self-healing ability to seal any hairline cracks in the concrete virtually eliminates further concrete-related maintenance or repair,” concludes Cláudio Neves Ourives.

The Jean Nouvel-designed 15-floor Mata Atlântica Tower is a highlight of the new Cidade Matarazzo complex in São Paulo, Brazil.

Waterproofed with Penetron technology: The Jean Nouvel-designed 15-floor Mata Atlântica Tower is a highlight of the new Cidade Matarazzo complex in São Paulo, Brazil.

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