If you change people’s perception, you can change the world!

ReTeto’s Attitude

We are ReTeto, an early stage start-up that offers a new sustainable roofing alternative, providing the favelas in Rio de Janeiro with a long-lasting roofing solution, while reducing the plastic waste that would otherwise end up in the ocean. 

Learn more about

The current situation in informal settlements

How ReTeto supports those neighborhoods before even starting the production

The overall impact ReTeto has on peoples lifes

Current situation in informal settlements

Sketch of the current situation in informal settlements

Informal settlements as the name already states are unplanned neighbourhoods where houses have been constructed on land that the occupants legally do not own. Due to the informal nature of these areas, infrastructure like water systems, streets, health and social systems are often barely existent. Narrow streets and shambolic city structures make basic needs such as stable electricity connection and proper waste collection nearly impossible. Trash is either burned (releasing toxic gases) or disposed in nature.

Besides waste management, adequate housing is a big issue in many informal settlements. Fast population growth, densely developed areas, and a do-it-yourself approach due to poor socio-economic conditions lead to precarious constructions everywhere. Buildings are seen as work in progress for each generation and consequently, often finishing touches are not relevant. Long-lasting roofing and proper insulation are important for each finished house, but if a house is seen as a construction site these characteristics get neglected. The vast majority of houses use metal tin roofs that cannot withstand the heavy rain during the rainy season, leak after a few years, and are catalysts for the urban heat island effect. Insufficient roofing impacts the lives of people in the community deeply.

Globally, about 1.8 billion people are living in conditions like described above. One example are the Favelas in Rio de Janeiro.  24% percent of the local population lives in such communities which equals 1.6 million people. From extremely poor to middle class, all levels of society are represented. The residents face a wide range of challenges, from sewerage and mobility to daycare centers and support for the elderly to waste collection. The lack of public investment is visible in many places. 

Two big issues in informal settlement are

79 % plastic gets accumulated in landfills or in natural environment as litter

By 2030: 40 % of world’s population will lack access to adequate housing

Let’s stick with Rio de Janeiro as location. The plastic presence in household waste in Rio de Janeiro was around 15,7% in 2020. Monthly, Rio de Janeiro produces approx. 3.4 tons of PET waste. According to the waste atlas, the recycling rate in Brazil is about 1%. Consequently, most of the plastic waste ends in landfills. On the other hand, most houses in the favelas have leaking roof sheets and an unstable construction basis which has a heavy impact on the way of life.

This lack of proper roofing and the abundance of plastic resources in informal settlements inspired the idea for ReTeto. “Teto” is Portuguese for “roof” and the “Re” comes from recycling. ReTeto’s goal is to gather used plastic locally and transform it into roofing sheets 100% made from recycled plastic for a fair price. The point of view on plastic has to shift from burden to resource.

This is how ReTeto works  

Firstly, local waste pickers collect plastic in their community and bring the plastic sorted to ReTeto. For the plastic, the waste pickers become a fair salary. Working as a waste picker is common in many countries in the Global South – in Brazil roughly 800.000 people work as waste pickers. Moreover, ReTeto will collaborate with the local disposal company COMLURB (Companhia Municipal de Limpeza Urbana) to increase the city’s recycling ratio and reduce the amount of waste ending up as landfills. 

0. Plastic Collection

First changes in informal settlement get already visible  

Sketch of the situation in informal settlements without plastic waste

Besides offering an adequate salary to waste pickers, the local community benefits from a cleaner environment as well. Plastic that would have ended up as waste in the streets is converted into a valuable resource. Plastic is taken out from nature and does not pollute the environment and local citizens. Trash that was previously either burned or disposed in nature is now reused. Consequences are that with the following rainfall, plastic no longer ends up from the streets into the sewer, into water bodies, and later in the ocean which could have caused pollution of water, harm aquatic life, and cause flooding through clogging of pipes. Through a durable and affordable circular economy of plastic in the informal settlements, all these points can be reduced. Furthermore, up-cycling unused material also creates jobs and helps to lift people out of poverty.

1. Sorting & Cleaning

The plastic from the waste pickers or COMLURB is again sorted after plastic type, quality, and color. Before the next step, the plastic needs to be cleaned properly and all labels need to be removed. Plastics that are not suitable for roofing tiles can be up-cycled to another product. or sold to other companies focusing on that plastic fraction.

Afterwards the plastic is shredded and properly stored. This process gives the possibility to produce roofing sheets in different colours and incorporate design into the roofing sheets.

2. Shredding

3. Molding into shape

The plastic flakes are put into a roofing mould. The first prototype is a rectangular, 8 mm deep plastic sheet made 100% from PP. The mould is put into the oven until the flakes get malleable again.

When the plastic resource in the mould is deformable, the mould is taken out of the oven and put in the press. The roofing sheet is compressed into a stable form with the correct properties.

4. Pressing

And then it is done in only four simple steps 

Picture of ReTeto’s first Prototype

ReTeto’s total impact

Sketch of the situation in informal settlements without plastic waste and proper roofing

This innovative roofing solution will improve more quality of life in informal settlements. The recycled plastic roofs provide insulation, they are water-resistant, and will not be quickly damaged by exposure to the sun. Roof tiles from ReTeto are expected to last at least 10 years, and it comes with a two-year warranty. Residents can live comfortably, in homes that are more protected from the heat, and without the threat of leakage. Moreover, they will no longer be forced to repair their leaky roofs every couple of years.

Besides providing a healthier and eco-friendly environment, ReTeto gives people in weakened financial situations the chance for proper roofing. Such a progressive solution for roofing is especially relevant in informal settlements as proper housing is crucial for access to jobs, education, health, and social services.

ReTeto can improve better housing conditions for people globally who are underserved and heavily impacted by the effects of climate change. We aim to reach this goal by following a triple-bottom-line approach serving all dimensions of sustainability. The addressed dimensions are social, economic, and environmental impact. Additionally, our efforts align with SDG and ESG goals.

And this comes next for ReTeto

Currently, ReTeto works towards developing a roofing prototype made 100 % from PET plastic. By the end of the year, a preliminary version of the roofing sheets should be developed and installed on a roof in Rio de Janeiro for testing. Besides working on product development, communication is the main focus. Because creating impact is ReTeto’s main goal, engagement and involvement of people worldwide is key, especially the local population. That is why ReTeto currently looks for partners who are eager to take the next steps together and help to change people’s perceptions.

The Team

Josina Wittenberg – MSc Climate Change at KU

Contact me: s203330@student.dtu.dk

Franca Bauer – MSc Environmental Engineering at DTU

Contact me: s202508@student.dtu.dk

Rosalie Orth – MSc Computer Science at DTU

Contact me: s192221@student.dtu.dk

Enrique Nicolas Quiroz Salazar – MSc Business Analytics at DTU

Contact me: s193187@student.dtu.dk