Green Roofing Systems the Need of the Hour in Egypt 5 From 7

The researchers compared the effects of green surfaces in nine cities around the world, including sub arctic Montreal in Canada, temperate London in the UK, humid Mumbai (India), and tropical Brasilia (Brazil).

In all cases, they studied the month during which that city ,sees its hottest temperatures by representing the microclimate around and inside buildings using computer modeling.

They compared local temperatures when buildings were made of bare concrete with when the concrete was covered in vegetation.

Vegetative roofs help to cool the surrounding air through evapotrans- piration, as the plants use the heat in their surroundings to evaporate the water in their leaves.

Filtrate Air

Plant surfaces can remove certain pollutants from the air thrush dry deposition.

A green roof can remove particulate matter (PM) and gaseous pollutants, including nitrogen oxides (NOX), sulfur dioxide (SO2), carbon monoxide (CO), and ground-level ozone (O3) from the Air.

Researchers estimate that a 1,000-square foot (93 m square) green roof can remove about 40 pounds of PM from the air in a year, while also producing oxygen and removing carbon dioxide (C02) from the atmosphere.

22 Forty pounds of PM is roughly how much 15 passenger cars will emit in a year of typical driving.

Green Roofing Assembly

A green roof system consists of vegetation, growth medium containing primarily of Lightweight inorganic mineral materials (at least 80 percent) and up to 20 percent organic materials like topsoil, moisture retention mat, drainage panel to help the excess water from the growing medium to flow to the roof drain, a filter membrane that allows excess water from the growing medium to flow out, while preventing the fine particles from washing away and clogging the roof drain, root barrier to protect