Greening The Roofdeck
Green roof is a flat surface on the top of any vertical structure planted with vegetation. It provides a protective canopy for the structure, shielding it from the adverse effect of nature. It is an ancient practice with a lot of common sense that could be very beneficial if put into wide practice in this era of global warming. Simply put, it is like wearing a hat when we want to protect our noggin from harsh weather elements.
Modern buildings are primarily made of concrete,with flat roof decks that is perpendicular to the sun at noon. Concrete by nature absorbs heat from the sun and the surrounding air. Absorbed heat will then be released on the other side which is inside the building, and since most were constructed without natural ventilation, the energy cost to cool down the interior will be substantially higher. Furthermore,the extreme difference between the interior and exterior temperatures will lead to moisture build-up creating havoc on the interiors’ finishing and will also affect the concretes’ strength in the long run. The usual remedy is the more expensive thermal insulation installation but green roof is the more cost effective, eco-friendly solution to this problem.
Green roof will deflect or absorb most of solar heat. The flora will regenerate the surrounding air, releasing much needed oxygen into the atmosphere. On winter,the plants and shrubs will soften the impact of raindrops and its’ roots will retain part of the rainwater which will otherwise run down the surface of the roof thereby reducing concrete degradation. For older structures, putting plants and shrubs in pots and boxes will do the trick. Some eco-friendly buildings were already designed with roof decks capable of being planted with small trees and shrubs. Stones and pebbles were laid under the top soil to filter rainwater. Voids were incorporated inside the posts and columns to channel the filtered water to the underground cisterns for future use.
The shade and ambiance created by the green roof could be utilized for the relaxation of the building occupants. A garden anniversary dinner looks fancy enough but an anniversary dinner on a 28th floor garden is as memorable as your wedding day.