There is a mistaken belief, still persistent in the Brazilian real estate market, that exposed concrete is synonymous with unfinished construction or a budget-saving choice. In contemporary high-end architecture, well-executed exposed concrete is exactly the opposite: it is the most demanding, the most expensive to execute correctly and the most honest material a building can use.
Structural Honesty as a Principle
Exposed concrete is the materialization of an architectural philosophical principle that traces back to Le Corbusier and the São Paulo brutalist movement: the structure of a building should not be hidden under layers of cladding — it should be celebrated, visible, integral to the aesthetic composition.
When 8HAUS specifies exposed concrete in a project, we are not choosing a finish. We are asserting that the building’s structure has inherent beauty and deserves to be seen. This imposes technical execution responsibilities that do not exist when ceramic cladding or paint over the surface is planned.
What Distinguishes High-End Concrete
The quality of exposed concrete is determined across multiple stages, long before the formwork is assembled:
Mix Design
High-end exposed concrete requires a specific mix for aesthetics beyond structural strength. The water/cement ratio must be rigorously controlled — excess water creates pores and segregation staining that cannot be repaired after stripping. We use concrete with fck 30 MPa to 35 MPa with plasticizing admixtures that reduce the w/c ratio without compromising workability.
Formwork and Texture
The final texture of concrete is the exact negative of the formwork’s inner surface. High-quality plastic-coated plywood formwork (18mm+) with rigorously aligned joints produces the smooth, homogeneous surface we associate with prestigious architectural concrete. Any imperfection in the formwork — a poorly sealed joint, a mispositioned bolt, an undulation in the plywood — is permanently imprinted in the surface.
Consolidation and Curing
The vibration of concrete during placement is decisive for eliminating air bubbles that create the undesirable “honeycombing” on the surface. In high-end projects, we require immersion vibration at controlled frequency with operators specifically trained for architectural concrete. Wet curing for a minimum of seven days after stripping is mandatory for chromatic uniformity.
Construction Joints as Compositional Elements
In extensive pieces, construction joints — the horizontal line marking where one pour ends and the next begins — are inevitable. In ordinary exposed concrete, these joints are irregular and compromise aesthetics. In high-end concrete, they are planned as compositional elements, aligned with openings, plane changes and other architectural elements.
Applications in 8HAUS Architecture
In our work, exposed concrete appears in specific and intentional contexts:
On exterior facades, when the architectural program calls for visual weight and permanence — as in the service volume of the Glass and Concrete Residence in Sorocaba, where the concrete monolith creates a deliberate counterpoint to the lightness of the glazed volume.
On interior slabs and beams, when the decision is to work with full ceiling height and exposed installations — as in the Executive Office Sorocaba, where the exposed slab with graphite-painted conduits is the unifying element of the entire composition.
As a feature wall, on a single plane that anchors the space — a curation strategy that maximizes the material’s impact without the risk of visual overload.
Maintenance and Longevity
Well-executed exposed concrete, protected with a clear water repellent in the first week after stripping, has a durability comparable to the building itself — decades without intervention beyond periodic cleaning with water and neutral detergent. The natural patina that concrete develops over time, far from being a problem, is part of its growing beauty.
It is the most honest material architecture knows: it does not age badly — it simply ages.