Designers Marco Merendi and Diego Vencato have collaborated with Italian firm Gypsum to develop a dirt-resistant concrete, which they used to create a collection of bathroom furniture suitable for outdoor use.

Milan-based architect Merendi and Veronese industrial designer Vencato used the new material to create the Petra collection of bathroom furniture for Italian brand Agape.

The collection comprises a washbasin available in a countertop or freestanding version, along with a separate countertop surface for the sink to sit on and a shower tray. The freestanding sink is fixed to a column incorporating the accompanying brassware.

Petra features on the longlist for the Dezeen Awards 2019 in the Furniture design category, alongside a range of furniture and homeware made from marble and volcanic stone, and a flat-pack furniture collection produced using recycled plastic bottles.

Vencato and Merendi had proposed a range of concrete products to Agape back in 2014 but the company had yet to identify a type of cement with appropriate characteristics for this application.

The designers worked with Emanuele Perego of plaster and stone specialist Gypsum to develop a high-performance concrete called Cementoskin that is resistant to any sort of dirt and can be moulded to create delicate forms.

"It is a new material, a mixture of cement enriched with carefully selected aggregates," the designers explained.

"The new form of concrete is a conglomerate with high-performing technical and structural characteristics, even when used in very thin layers," they added. "And, very importantly, it’s a water-based material so is completely eco-friendly."

The studio used the material to create a collection featuring shapes inspired by smoothly eroded pebbles. The natural aesthetic of the products is reinforced by the soft-touch quality of the concrete surface.

The concrete is dyed with oxides during the mixing process to produce a range of 12 different tones, including three neutral greys and a variety of greens, blues and warmer hues that all evoke colours found in nature.

The material's unique properties make it suitable for indoor and outdoor use in a range of contexts including private and public environments. It is resistant to staining, chemical corrosion, extreme temperatures and salt mist.

The designers outlined various potential usage scenarios for the Petra products, including "large gardens and small terraces" as well as more typical bathroom environments.