Green Roof And Cool Roof

Which system or combination of systems is most appropriate for an individual roof will need to be evaluated on a case by case basis.

Green roof and cool roof. Green roofs are also referred to as eco roofs oikosteges vegetated roofs living roofs greenroofs and vcp h 8 horizontal vegetated complex partitions. By doing this cool roofs allow for a more comfortable and controlled indoor environment. Cool roofs reflect solar energy. Cool roofs are even cheaper than green roofs only costing 0 75 to 1 50 per square foot and a single ply cool roof membrane usually ranges from 1 50 to 3 per square foot according to epa gov.

After selecting to use a green roof or cool roof the roofing contractor must look at the pros and cons of each in order to decide which would be best for the property. Green building council and the department of energy building technology program base their respective cool roof credentials on a roofing material s ability to reflect the sun solar reflectance and release absorbed heat emissivity. A cool roof prevents heat absorption by reflecting the sun s heat and then emitting its radiation back into the atmosphere. Green roofs may not reflect as much as a cool roof but do have other benefits such as evapotranspiration which cools the plants and the immediate area around the plants aiding in lowering rooftop temperatures but increasing humidity naturally.

A green roof or rooftop garden is a vegetative layer grown on a rooftop. Green roofs use soil and vegetation as living insulation. Green roofs are ideal for urban buildings with flat or shallow pit roofs and can include anything from basic plant cover to a garden. Although cool roofing is one of the most significant green technologies today it is not a new concept.

Using green roofs in cities or other built environments with limited vegetation can moderate the heat island effect particularly during the day. The primary reasons for using this type of roof include managing storm water and enjoying a rooftop open space. Moreover some green roofs need maintenance such as regular watering. Green roofs provide shade remove heat from the air and reduce temperatures of the roof surface and surrounding air.

Cool roofs reflect sunlight and heat back into the atmosphere while green roofs help absorb the sunlight and heat before it can enter the building. While the term cool roof is sometimes used to describe any roofing surface that is cooler than a standard rooftop green certification programs such as leed energy star the u s.