Narrator: These tiles are made with smog.
Black soot gets baked into their cement designs.
The founders of the Indian company that makes them
say this is a major step toward a new era
of sustainable building.
But how do they get tiny airborne particles
into a solid material?
And can these really make a difference
in a country with some of the world's worst air quality?
Black carbon comes from burning fossil fuels.
It's the stuff that darkens the skies over Indian cities.
It's dangerous to breathe,
it reduces crop yields,
and it contributes to global warming.
So how did India's air quality get so bad?
It starts at home, where many cook with wood and dung.
Both create a lot of smoke.
And then there's traffic.
The number of vehicles on the road
has more than quadrupled since 2003.
Pollution is worst at the onset of winter.
That's when farmers burn agricultural waste.
Diseases triggered by air pollution
kill over 1 million people in India every year.
That's 10 to 20 times higher than the rate
in the United States.
The good news is that black carbon is short-lived.
It only stays in the air for a few weeks.
It's not like carbon dioxide,
an invisible gas that can warm the atmosphere for centuries.
The problem is that people in India burn so much stuff,
the air never has time to clear.
So preventing black carbon from getting up there
in the first place could make a difference.
That's the big idea for Tejas Sidnal, an architect
and the inventor of Carbon Tiles.
Tejas: This carbon is what is in your lungs
and my lungs right now.
I'll show you around how our office looks like
and what we do.
Narrator: He launched Carbon Craft Design in 2020
to create marketable products that upcycle waste.
Tejas sources most of the carbon
from companies that would otherwise
release it into the atmosphere,
like this facility that recycles tires.
The factory produces loads of black carbon
that usually gets sold as cheap fuel.
But when that gets burned,
it puts the pollution back into the atmosphere.
Carbon Craft interrupts this cycle
and puts the toxic powder in its tiles.
Tejas: It comes in these huge sacks
dry and absolutely pitch black.
Narrator: The sacks go to a factory
that has been making tiles by hand for 35 years.
Many mass-produced tiles
only harden in kilns burning at high temperatures.
But Carbon Tiles made from cement are never baked,
so the process doesn't require a lot of energy.
Tejas: This is also the lowest carbon footprint
way of making a tile.
We thought, why don't we adopt this?
Narrator: Tejas places an order
whenever he secures a new customer.
The workers follow a process
that's been around for over 200 years.
Now, they replace some ingredients with black carbon.
Narrator: Once the powder reaches a smooth consistency,
they mix it with water to create a slurry.
The amount of black carbon in the mix
determines the shade of the cement.
Narrator: It takes skill to get the consistency right.
Too much water and the tile won't hold together.
Too little can ruin the pattern.
Every design has its own metal stencil.
Workers pour the slurry into the voids.
One of the hardest parts is to get crisp lines,
so workers have to move quickly.
Tejas: Remove that stencil at a flick
so that it doesn't have a distorted design.
Narrator: And then they add the backing layer.
That also has carbon.
Tejas: The first layer is more for
the aesthetics and the pattern that really comes out.
The back layer is for strength.
Narrator: The factory's only hydraulic press
squeezes the tile into shape and helps it set.
Narrator: The firmed-up tiles still need to strengthen
through a process called water curing.
That means they get hosed down every day for nearly a month.
Narrator: Workers give the fully cured tiles
a rough polish
and a final rinse before they get packaged for sale.
All carbon tiles are made to order.
The company says it can make as many as 200 of them
in a day.
Tejas: The cost of one tile is less than $2.
Narrator: That's comparable in price to cement tiles
that don't contain carbon.
Tejas: The biggest order we've had was about 100 square feet.
Narrator: Carbon Craft has only done about
10 installations across India in the past year.
They consider these pilot projects.
Tejas: At the moment we are working with a lot of
architects, interior designers
who are keen to solve this larger problem of air pollution.
Narrator: Like Manan, a general contractor in Mumbai.
Manan: So these are the carbon tiles
that we've installed in my room,
basic 8-by-8 slabs in plain gray color.
This was the first time they've ever been
installed anywhere in the world.
Narrator: But installation is tricky.
Cement tiles require a lot of extra polishing
even after they're put in place.
Manan: So it could range anywhere between
three to four sets of the whole process,
which is about, say, 15 to 20 odd days.
Narrator: Other mass-produced tiles
that harden under high heat skip this part.
But Manan's business partner
says the benefits to the environment outweigh the drawbacks.
He's happy with the results
and recommends the tiles to clients.
Adish: And it is something
very small that we're doing right now,
but you know, it can have a big impact to people on a larger scale.
Narrator: Tejas got the inspiration for carbon tiles
when he was a graduate student.
Tejas: I've always tried to see how we can make buildings
which are inspired from nature,
and nature doesn't have any waste.
Narrator: For his team members,
the motivation to tackle air pollution is personal.
Aniket: I got asthma. It's from childhood.
I have suffered a lot because of air pollution.
My family, my father and my sister,
are allergic to everything.
Narrator: But he's relying
on this small group of architects and designers
to take Carbon Craft to the next level.
Tejas: Once we're able to scale this
to 1 million square feet,
we'll be able to get into the mass affordable segment
from here.
That will have a large-scale impact and applicability.