White, Blue, and Green Roofs

This might be new to our ears, aside from the commonly known roofing types such as asphalt shingles, slate and tile shingles, metal roofing, and flat roof, there is actually roof types named before colors – green, blue, and white roof. Well, we can always call any type of roof as blue roof if it is painted blue, green roof if painted green and white if painted white. But obviously, that’s not what we are going to talk about. These types of roofs might have something to do with its name, but they’re more than colors.


Let’s start first with the white roof.

White Roof 

White roof is also known as cool roof. It is painted with white coating that reflects sunlight up to 90%. It can bend during hot days because of its elastic property. Its solar reflecting property gives numerous benefits. Reflecting light means cooler building which minimizes energy use 10% to 40%, thus saving money from air conditioning. Since it lowers waste energy of ACs and other machines, it also lowers down the smog and CO2, which mainly causes global warming and climate change. Aside from these, having a cooler roof extends the roof life span because it prevents warping and cracking thus reduces roofing waste (another plus for the environment).

However, there are new studies that disputes it effect on the environment. Yes, it reflects light and heat, but that is not always a good thing. These suggest that the “cool” temperature is only in the roof level. Reflected heat is actually directed into atmosphere and is then mixed with black and brown soon particles which contribute even more to global warming. It might lower the waste energy from the air conditioning but not more than on how it increases the heat in the atmosphere. Aside from that, having cooler roof collects moisture on the surface of the roof thus inversely affects the algae growth.

Blue Roof

Blue roof is designed to hold rainwater temporarily during a rainstorm. This is best applicable to urbanized cities that have combined sewers. Keeping the rain water from reaching the sewers prevents the sewers from overflowing. Blue roof will then slowly release the rain water when the sewers are already capable of receiving it without overflowing. This protects the local streams, ponds, oceans, or other natural resources like fishes and vegetation from being contaminated.

Green Roof

Green roof is a type of roof that is completely or partially topped with vegetative layer, hence it is also known as living roof. It requires layers such growing medium and drainage layers. Although it is costly upon installation and structural requirement since it is heavy, it can save you money in the future because it is low cost maintenance. Aside from its environmental sustainability benefits (e.g. air and noise pollution treatment, natural cooling properties, and UV absorption), it is long lasting, from 30 to 50 years of life span depending on the maintenance and structural support and layer designs.