Like thousands of other people in Cairo, Ashraf Ali, 33, has lived his whole life on a downtown roof.
Seven floors above the dirt and din of Cairo's streets, he enjoys a cool September breeze that sweeps over the one-room clapboard hut he shares with his wife and two children.
"In the summer we eat, drink, and sleep out here," he said, gesturing toward the dusty rooftop, where the rent is less than $1 a month. "It's better than living down there."
Some Cairo roof-dwellers enjoy makeshift toilets, standpipes, even baths. For others, there is no running water and little protection from scorching summer sun or winter rains. Of this 'sub-class', the luckier ones can rely for water and toilets on the hospitality of better endowed neighbors in flats 'below'.
"We have no money to buy an apartment," said Gez Zeedan Mohammed, 70, who grew up, married, and raised three kids on a nearby downtown roof. "Where else can we go?"
Hundreds of thousands of Egyptians who flooded into Cairo during an economic boom in the 1970s had no money to rent an apartment, and instead set up houses on the city's rooftops.
For some of their children, life on the rooftop is a reminder of the failure of Egypt's current economic boom to improve living standards for the poor.
Others say it's not such a bad life. Rent is cheap, work is nearby, and perhaps most importantly, they feel removed from the clamor and crowds down below.
"Life on the roof is wonderful because of the breeze and the sun," said Ibrahim Mahmoud, 67, who raised three kids in a shack 12 stories above the street.
Mahmoud, who works as a telephone operator at a plastics company a few blocks away, came to Cairo 35 years ago from southern Egypt and chose to live on a roof because it was cheaper.
Now, he pays less than $4 a month and says a comparable apartment lower down could cost 10 times as much.
Nearly half of Cairo's population of about 14 million live in areas that are unplanned or unserved by plumbing, said Abouzed Rageh, former chairman of Egypt's National Research Center for Housing and Building.
"Most investment whether for production or services is in the region of Cairo," Abouzed said. "This is the reason behind migration from rural areas to the big urban center."
Egypt's economy grew at its fastest rate in two decades last year, drawing even more people to Cairo, where an average of about 70,000 people cram into each square mile, a population density greater than Manhattan's. "Cairo is growing at an uncontrolled rate," said Madiha el Safty, a sociology professor at American University in Cairo and a writer on housing issues. "Informal housing can be a very pragmatic solution."
But the crowding can lead to unrest. Protesters blocked highways on several occasions during the summer over a lack of drinking water in some areas of Cairo.
"The government talks about the informal housing problem but very little has actually been done," Abouzed said.
For some, living on a roof is at least better than sleeping on the street.
Nadia Awad Hassanein, 55, moved up to a wooden shack on the roof in a part of the city called Old Cairo 10 years ago. She sleeps there, she says, because she has no work and no source of income.
Every evening, she climbs a ladder up to the shack, which is covered by old tires and rusted metal scraps to keep out the winter rain.
"When it gets really hot, I sleep outside on the roof," she said.
On some of Cairo's larger roofs, communities of families can develop in an environment preferable to the one below. Rooftop communities often interact only with each other, using separate stairways that bypass the rest of the building.
Mahmoud Ragab, 48, has lived on the same roof as Ashraf Ali since his childhood.
Four different families live on the roof, often gathering outside in the afternoons or evenings.
"We are one family up here, like brothers," he said.