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Summer 2013 Blog - Leo Brossollet

Leo Brossollet is spending eleven weeks in Ahmedabad, India working at ModRoof.

September 17, 2013


A waterproofed panel.

It’s hard to believe I’m already back at school in Berkeley.  Just a month ago I was on the other side of the globe.  Since then, ModRoof has finalized a manufacturing process that will lend easily to scale, and we’ve been working on our waterproofing.  Our main focus has shifted to the roof installation process, and we have made a model house to try and experiment with different support structures.

We’ve since changed the company name to ReMaterials, and launched a website. In addition to moving forward with our ModRoof project, we’ve also begun to look at other applications our panels could have.  The most urgent goal is still to provide roofing, but we believe that our material could be a sustainable wood alternative for construction and furniture applications.


A model house built from the roofing panels.

Looking back on my time with ModRoof, I learned things and gained skills that I had no idea would come in to play during my internship.  Although my internship had a focus on the technical aspect of turning recycled waste into roofing, I witnessed first hand not only the drawing board calculations but also the footwork and elbow grease that goes into bringing an idea to fruition.  Time and time again we realized that we had taken a wrong turn, and we had to scrap our progress from that point and reset the process.  Since we don’t have our own factory yet, another part of my work had to do with cultivating and maintaining a relationship with metallurgists, waste collectors, and factory owners.  This enables us to still produce panels until we have our own factory.  Equally important are the relationships forged with families that will be using our roofs.  By keeping our ear to the ground and ensuring the spread by word of mouth, we will be able to reach more people and have a bigger impact.

It’s been great to gain another perspective on the problems that our facing our world.  Energy and sustainability are becoming more and more important as new economies grow and populations increase all over the globe.  Even once we solve the problems that the world faces today, new issues will crop up and require more innovative solutions.


Leo’s last panel.

Although the summer has ended, I will continue to be involved in the ModRoof project, and I will definitely never forget the lessons learned and knowledge gleaned from my 11 weeks in Ahmedabad.  If you’d like to know more about ModRoof and my time in India, please feel free to shoot me an email. Thanks for reading!

August 2, 2013



Humayun’s Tomb in Delhi.

The past two weeks have made up some of the best time I’ve spent in India so far. Great progress has  been made at the factory – we’ve reduced our production time drastically by implementing a new mold design.  We drilled holes in the top of the mold, which allows water to escape more efficiently during compression.  Previously  it took us several hours to compress material, however now it takes only fifteen minutes.  Furthermore, with this new innovation in the mold design the panels have become denser, which greatly increases the strength of the panels.  We have sent our latest panel to the laboratory for testing for strength and insulation, and will soon be doing in-house waterproof testing.

I also got a chance to do some site-seeing since my last post.  The weekend before last I went to New Delhi and Agra.  My coworker Erin and I traveled by train on the Rajdhani Express in a sleeper cabin.  The ride was long but smooth, and we were served a “snack”, dinner, evening tea, and breakfast with tea.  Indians probably drink tea around five times a day, and it’s always Chai.

While in Delhi we had time to see several sites: the Qutub Minar, a large tower located on an archeological site; Humayun’s Tomb, sometimes called the little Taj Mahal; and the Lotus Temple, a modern structure built for worship by the Baha’i.  I was literally drenched in seconds by the most intense rainstorm I have ever been in, and it rained on for four hours.  The streets were so incredibly flooded, waterlogged car engines broke down and “rivers” filled the streets.


Leo at the Taj Mahal in Agra.

On our last day, we headed to Agra to visit the Taj Mahal.  Words struggle to describe this wonder of the world, but it was majestic and humbling, and well worth the seven hour round trip.  Shah Jahan, Indian emperor of the then powerful Mughal Empire had it built, starting in 1632, for his third wife, Mumtaz Mahal after she died giving birth to their fourteenth child.  It is a classic example of the Mughal architectural style, which combines Persian, Ottoman Turkish and Indian elements.  The complex uses mostly white marble and red sandstone, with black onyx for accents.  The fauna is meticulously gardened to enhance the pristine and immaculate aura of the Taj, and when you pass through the “gateway building” the tomb immediately dominates the horizon, looming massive a kilometer in the distance. Intricate inlay work on the white marble tomb incorporates lapis lazuli and other precious gems.  The entire complex is symmetrical along the north-south axis, from the smallest curve of a marble flower to the distance between the leaning minarets, and all of the buildings are also symmetrical along their west-east axis.    When entering the main structure, shoes are taken off or cloth covers are applied, a common practice in temples, mosques, and otherwise sacred places in India.  After a two hour tour of the Taj Mahal, we headed back to Delhi, and then hopped on the Rajdhani Express back to Ahmedabad.


Leo and his colleague in Delhi at the Qutub Minar.

This past weekend we visited the Akshardham Gandhinagar complex, the capital city of Gujarat, about 20 minutes away from Ahmedabad.  The complex not only includes a temple but also a water and light show and an amusement park with carnival rides.  The complex was built by the Hindu sect of Swaminarayan, who regard Lord Swaminarayan, who passed on in 1830, as the reincarnation of God.  The temple was resplendent and on the ground floor featured a shrine to Swaminarayan consisting of three gold leaf covered statues.  Unfortunately, however, cameras and phones were confiscated at the entrance.  Also in Ghandinagar is the Adalaj step well.  Built in 1499 it consists of a series of sunken steps descending to the well which is five stories below the surface.  It was originally a highly utilitarian structure, despite the intricate decorative carvings, used to collect rainwater during monsoon season.

It’s hard to believe that I only have two weeks left in India!  Hopefully they will pass by much more slowly than the past two months have!  I guess time flies when you’re in a new country. That’s it for now, I’m going to try and make the most of what little time I have left.

July 18, 2013


Monsoon brings heavy flooding throughout Ahmedabad, especially in the Old City, where drainage infrastructure is lacking. The green and yellow vehicles are auto rickshaws, which run on compressed natural gas and will take you anywhere in the city for less than three dollars!

Monsoon is in full swing in Ahmedabad, but the ModRoof team have been working rain or shine since my last post.  Besides cranking out panels, which are now coming out smoother and stronger than ever before, we have been looking into how to incorporate solar energy into the panels.  The plan is to incorporate solar energy in such a way that it would be able to charge a 12 volt battery over the course of a day.  Families living in urban slums consume relatively small amounts of electricity, and in fact many already meet their needs using only a single 12 volt battery.  If we were to incorporate solar energy into the panels, it would save the families money and a trip to the store, as well as reduce their carbon footprint, as a rechargeable battery is much more sustainable than a traditional one.


One way to incorporate Solar Energy – a roofing panel with a small solar panels.

The picture to the right shows one of the ways we might incorporate solar energy into our panels.  You might recognize the paneled structure from your front yard.  In fact we are using the same type of panels that are commonly used to light garden walkways.  We simply stripped the original structure of its light and mount, leaving only the protective metal casing and the panel itself.  By incorporating twelve or so of these panels into our roofs, they can be used to meet the needs of the average family.  Furthermore, the increase in cost of the entire roof is small on a per square foot level, making this improvement economically viable.

Work aside, last week I had the chance to go to a unique restaurant.  At Seva Cafe food is served with the spirit of “Atithi Devo Bhava,” or “Guest is God”, and your meal is technically “free”.  They liken it to offering your friend a meal when they come to your house, only in this case, the gift is extended to a stranger.  The clients themselves also participate in this spirit at the end of the meal.  Although your food has been paid for, at the end of the meal you are presented with an envelope, and invited to contribute as much or as little as you like.  You are not paying for your food, but donating in order to cover the cost of the next person who comes to eat at Seva Cafe.  They’ve coined this system “Gift Economy”.  Within this pay-forward system, contrary to what you might expect, people tend to contribute more than the cost of their own meal, and Seva Cafe is thriving.  They also run a clothing and gift shop next-door, which employs young women living in slums to make clothing, bags, and other products.


The Modroof Team grabs dinner at Seva Cafe. From left to right: Leo; Erin, a third year Materials Science student at Stanford; Ashish, who just finished his masters at Cal in the Civil Engineering Department; and Hasit, founder of ModRoof.

We also got the chance to go on a historic Heritage Walk through the walled Old City.  We began at the Mangaldas Ni Haveli, a 200 year old house in the heart of the old city.   It features amazingly intricate woodwork throughout, an open air third floor meant to let hot air escape, and a rainwater collecting system that fills an underground well.  We continued on through the old city, as our guide explained to us, the system of how the old city is divided into puls, or districts, which have their own gates that were previously closed at night and guarded by a watchmen who lived above the gates.

Our walk culminated at one of the gates which still stands, where we got to watch as the watchmen played drums to signal the closing of the gates.  This ritual dates back 600 years to the founding of Ahmedabad.

That’s it for now.  This weekend I’m taking a trip to New Delhi and the Taj Mahal, so I’ll post again soon!


July 3, 2013


The new oven being used to dry the panels. The left side is the oven on and on the right the oven is off.

We took a big leap forward today at the factory. While I have been in Ahmedabad we have been repeatedly making and testing panels, altering different aspects of the manufacturing process (most notably the mixing proportions and the drying process). For our last panel we came up with a new “oven” design. Two electric heating coils were placed above and below the clamped, drying panel. Intake fans were placed at the front of the oven and outtake fans at the back. Finally, the entire interior was covered in aluminum foil to ensure minimal heat loss.

After a few days spent applying foil, purchasing heaters and fans from the market in the old city, we headed to the press with some fresh made material and packed it into the press.  Once we started cooking the new panel, we immediately noticed an improvement form previous ovens.  The maximum temperature was much higher, and the air circulation was doing a good job of removing moisture.


Leo and his colleague loading up the panel for testing.

Today we removed the panel to find that for the first time we had successfully removed all of the water from a big panel via the new oven design.  Thrilled, we looked towards testing this new panel’s strength, as we routinely do with all the panels.  For our crude in house tests, we simply place the panel on two supports and increase the load in the middle.  While previous panels had been breaking at loads of only 70 kg (~154 pounds), this panel broke at over 250 kgs (~550 pounds).

This is almost at our goal of 300 kg, which is our benchmark before we send a sample to the lab to find the exact load at which the panel fails.  Once at the lab the panel will also be tested for insulation.  From that point onwards, we will be able to apply waterproofing coatings to new panels and install a prototype in a slum, instead of piling weights on top of them until they break!

June 26, 2013


Mr. Pardeshi in his factory.

Hello again from Ahmedabad, where peacocks roam free and traffic lights don’t exist.

After almost a month of working at ModRoof, we have come closer to creating a perfect 2′x2′ panel, nearing our ultimate summer goal of creating a demo roof for in-house testing as well as installing a prototype in a slum neighborhood.  As we come closer and closer, I’d like to break down the effort it takes to create each panel.

First, we need to prepare material for compression.  We purchase cardboard from a trash collector near Hasit’s house.  Then we tear the cardboard into smaller pieces removing any tape or staples that may be found therein. The cardboard is soaked in water and poured along with the water into a blender.  A pulpy mixture with a texture similar to oatmeal is produced. To this mixture we add coconut fibers, and some other secret organic materials.
Next up is compression. For this we go to Mr. Ajay Pardeshi, who is co-owner of Acme Air Equipments Company Pvt. Ltd., a factory which produces blowers and exhaust systems for industrial machinery.


In order, this is the mold, packing of the mold, and a fresh “off the press” mold.

Mr. Pardeshi’s son is a longtime friend of Hasit’s, and therefore he allows us to use floorspace and the hydraulic press free of charge, he even has his workers help us.  Pardeshi is a mechanical engineer by trade, and our trips to the factory often lead to brainstorming sessions in his office.  He has seen the housing conditions in slums, and some of his workers actually live in them, so he is happy to lend a helping hand.

We arrive at the factory with our pre-made material and then head to the hydraulic press.

Placing the material in the mold as shown, we then compress it in order to remove excess water and force the material to bond.  Once we reach the desired thickness for our two foot square panels, pressure is released, the mold is opened, and the panel is slid onto a perforated metal sheet.

Once the panel is removed from the press, it still contains some water.  To remove it, we dry it in an “oven” we have built to “cook” the panels.  First, however, another perforated sheet is placed on top of the panel, and fastened to the lower sheet with bolts.  This is to prevent warping during the drying process.  Once the panel has dried, it is removed from the oven and released from the perforated sheets.

Much of this process is different from the one we used when I arrived: since then we have been constantly experimenting to create a better panel.  Hopefully, we are close to a result which will easily lend to scale and put us one step closer to putting a sound roof over the heads of potentially thousands.

June 12, 2013

Greetings from Ahmedabad!  I have been here for about two weeks now under the Cal Energy Corps program. It has been quite an adjustment, in terms of diet, jet lag, and of course the sweltering heat.  However, by now I can handle the local diet, my biological clock has flipped the required 12 hours, and monsoon season has come, raining away the 110+°F heat.

I am interning for ModRoof, a startup which is working on providing a solution to the roofing situation in urban slums in Ahmedabad, and ultimately all of India. Currently the situation is dire for the impoverished slum inhabitants.


A roof made from metal sheets loosely lain on top of the house, weighed down with the odd brick or piece of wood.

There are two options on the market when building a roof for a new house:  very inexpensive corrugated metal, or relatively expensive concrete slabs.  The inexpensive options are riddled with problems: they offer poor insulation from heat and rain alike, are not strong, and in the case of the metal panels, corrosion is commonplace.  See the picture to the right.

As you can see, the sheets of roofing seem to be loosely lain on top of the house, weighed down with the odd brick or piece of wood (a common practice). If a gust of wind or a dog running along the roofs were to cause a sudden shift, the entire roof risks caving in. Furthermore, during the hot months, the metal heats up, making the rooms within unbearably hot, and in the rainy months water finds its way between the sheets.  The concrete slabs solve all of these problems simultaneously, however they are much more expensive, and by the time a family has built four walls, there is often little money left for the roof.

At ModRoof we are creating a product that will solve all the problems presented above and it would retail for significantly less than the concrete option. We are also looking to implement solar energy into the equation.  So far Hasit Ganatra, the owner and creator of ModRoof, has successfully created nine inch square panels out of recycled cardboard, water, and other organic materials that meet the requirements for a sound roof.


An example of the large tiles that Leo is working on building.

Our goal this summer is to scale up this process to create larger tiles and hopefully create a prototype roof. My job is to streamline the manufacturing process with a focus on reducing bottlenecks in the production line. However as we have begun making bigger tiles, we have encountered new issues in the manufacturing process.  To the left is an example of a large tile (about 2.5 feet square) which warped during the drying process, and also came out with cracks in the surface.

This past week we’ve been making a new batch of big tiles, with daily trips to the factory where we use the hydraulic press for our manufacturing.  I’ll post back with more pictures once I catch a break!

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