ST Bungalow to demonstrate fiberglass roofing solution from recycled wind blades
ST Bungalow has so far 3D printed and tested miniature models of its fiberglass composite roof forming solution. Shown here, the molds are cast in arcs or other molds for maximum tensile strength. Photo credit, all images: ST Bungalow
Concept developer fiberglass and concrete roofing ST bungalow (Croton-on-Hudson, NY, USA) reports that it recently signed a Memorandum of Understanding (MoU) with a recycling company for the use of recycled wind blade material in ST Bungalow LLC’s patented flat roof concept.
ST Bungalow LLC, a spin-off of solar technology company Solar-Tectic LLC, was founded in 2013 with the original goal of developing a low cost, eco-friendly housing unit using a flat roof concept that could also support the installation of solar panels. The housing units – called “Bungalows” – are designed as a housing solution for impoverished areas. The walls would be constructed of compressed earth blocks (CEB), which have a low carbon footprint because they use very little concrete, notes Ashok Chaudhari, director and co-founder of both ST Bungalow and Solar-Tectic LLC. For the bungalow roofs, Chaudhari says the original plan was to develop a flat roof system from CEBs.
The fiberglass formwork serves as both the interior ceiling and a reinforcing structure for a thin layer of exterior concrete. Shown here as a miniature model.
While developing the Bungalow housing concept, Michael Mollinelli, an architect with whom Chaudhari and his team worked on the project, presented an idea for a roof design that was a stronger, more durable solution based on fiberglass composite. Patented in 2017 by ST Bungalow and Mollinelli, this idea involves a fiberglass composite formwork formed in one of several designs, with a thin layer of concrete on top. The total solution serves as both an exterior roof and interior ceiling for the bungalow, and can also be used for floors and possibly also for bridge decks.
Until recently, Chaudhari says, the fiberglass molds seemed prohibitively expensive to produce for the company to begin commercial production. “Our roof idea has now suddenly become very relevant through the recycling of wind blades,” he says. “The wind industry doesn’t have many uses right now for the fiberglass recycled from blades, but for us it’s the same material we need for our roofing product.” He says the recycled fiberglass composite is mechanically shredded into powder and then molded into a new compound with the addition of small amounts of new or recycled resin.
One of the advantages of the roof solution proposed by ST Bungalow is easy transport and installation. This drawing shows 28 trapezoidal shapes neatly stacked in one container.
This solution is intended to serve as a more durable, lower concrete alternative to corrugated steel roofs or concrete roofs reinforced with steel or fiber reinforced polymer (FRP) reinforcement. “The basic idea is that the shape and form of the fiberglass provides the tensile strength needed to push the concrete to maximum compression,” explains Chaudhari, minimizing the amount of concrete needed. Using composites also eliminates corrosion problems from moisture, and installing the system would also be easier and less expensive than installing rebar as it would take less time for workers to install, he says.
So far, the company has 3D printed and tested miniature models of the technology, and plans to build, test and certify full-size versions this year using recycled fiberglass. From there, ST Bungalow hopes to find construction and/or venture capital partnerships to scale up the technology for commercial production.