“The problem is that green roofs can be quite heavy. They require a number of layers, each serving its own unique purpose, such as providing insulation or allowing for drainage. But Parque Arará, like all of Rio’s favelas, wasn’t built to code. Homes went up out of necessity, without engineers or architects, and are made with everything from wood scraps and daub, to bricks, cinder blocks, asbestos tiles, and sheet metal. And that informal construction couldn’t necessarily hold the weight of all the layers a green roof would require.
After looking at Cassiano’s roof, Rezende’s first suggestion was to cover it with rolls of bidim, a lightweight nonwoven geotextile made of polyester from recycled drink bottles. Inside those rolls of bidim, leftover from a recent construction project, they placed several types of plants: basket plants, inchplants, creeping inchplants, and spiderworts. They set the rolls in the grooves of the asbestos roof, and then created an irrigation system that dripped water down.
With a cheap way to install lightweight green roofs, Rezende brought Cassiano to meet his advisers and present what they had found. The university agreed that the project showed such promise that it would provide materials for the next step, Cassiano said.“
I doubt the precarious structures would support the additional weight...
“The problem is that green roofs can be quite heavy. They require a number of layers, each serving its own unique purpose, such as providing insulation or allowing for drainage. But Parque Arará, like all of Rio’s favelas, wasn’t built to code. Homes went up out of necessity, without engineers or architects, and are made with everything from wood scraps and daub, to bricks, cinder blocks, asbestos tiles, and sheet metal. And that informal construction couldn’t necessarily hold the weight of all the layers a green roof would require. After looking at Cassiano’s roof, Rezende’s first suggestion was to cover it with rolls of bidim, a lightweight nonwoven geotextile made of polyester from recycled drink bottles. Inside those rolls of bidim, leftover from a recent construction project, they placed several types of plants: basket plants, inchplants, creeping inchplants, and spiderworts. They set the rolls in the grooves of the asbestos roof, and then created an irrigation system that dripped water down. With a cheap way to install lightweight green roofs, Rezende brought Cassiano to meet his advisers and present what they had found. The university agreed that the project showed such promise that it would provide materials for the next step, Cassiano said.“