ST Bungalow has so far 3D-printed and tested miniature models of its roof shape solution made of fiberglass composite material. Shown here, the shapes are molded into arcs or other shapes for maximum tensile strength. Photo credits, all images: ST Bungalow
The developer of the fiberglass and concrete roof concept ST Bungalow (Croton-on-Hudson, NY, USA) reports that it recently signed a Memorandum of Understanding (MoU) with a recycling company on the use of recycled wind blade material in the patented apartment of ST Bungalow LLC has roof concept.
ST Bungalow LLC, a spin-off from solar technology company Solar-Tectic LLC, was founded in 2013 with the original goal of developing an affordable, environmentally friendly residential unit with a flat roof concept that could also support the installation of solar panels. The residential units – called “bungalows” – were designed as a residential solution for impoverished areas. The walls would be built from compressed earth blocks (CEB), which have a low carbon footprint because they use very little concrete, notes Ashok Chaudhari, managing director and co-founder of ST Bungalow and Solar-Tectic LLC. According to Chaudhari, the original plan for the bungalow roofs was to develop a flat roof system from CEBs.
The fiberglass formwork serves both as an interior ceiling and as a reinforcement structure for a thin exterior concrete layer. Pictured here as a miniature model.
While developing the bungalow living concept, Michael Mollinelli, an architect from Chaudhari and his team with whom the project worked, came up with an idea for a roof structure that was a stronger and more durable solution based on fiberglass composite. This idea was patented by ST Bungalow and Mollinelli in 2017 and involves fiberglass composite formwork molded in one of several designs with a thin layer of concrete on top. The overall solution serves as both an external roof and an internal ceiling for the bungalow and could also be used for floors and possibly also for bridge decks.
Until recently, Chaudhari said, making the fiberglass molds seemed prohibitively expensive for the company to begin commercial production. “Our roof idea has suddenly become very relevant due to the recycling of wind blades,” he says. “The wind industry doesn’t currently have many uses for the fiberglass recycled from rotor blades, but for us it is the same material that we need for our roofing product.” He says that the recycled fiberglass composite is mechanically crushed into a powder and then added in small amounts new or recycled resin is formed into a new compound.
One of the advantages of the proposed roof solution from ST Bungalow is easy transportation and installation. This drawing shows 28 trapezoidal shapes neatly stacked in a container.
This solution should be a more sustainable, less concrete alternative to corrugated iron roofs or concrete roofs that are reinforced with steel or fiber-reinforced polymer (GRP) rebar. “The basic idea is that the shape and shape of the fiberglass allow the tensile strength required to push the concrete to maximum compression,” explains Chaudhari, which minimizes the need for concrete. Using composite materials also eliminates moisture corrosion problems, and installing the system would also be easier and cheaper than installing rebar as it would take less time for workers to assemble, he says.
So far, the company has 3D printed and tested miniature models of the technology and plans to build, test, and certify full versions from recycled fiberglass this year. From there, ST Bungalow hopes to find construction and / or venture capital partnerships to scale the technology for commercial production.