Why Are Roofs Black

However that is not the case when it comes to modern roofs.

Why are roofs black.

Why choose a white roof over black. Black roofs do not absorb heat in the winter under a foot of white snow. By reflecting up to 88 of the sun s energy duro last s white membranes can greatly reduce energy consumption and costs making it an. You don t have the option to reflect sunlight.

Since black roof shingles absorb the energy from the sun you lose the option to reflect the sunlight to create a cooler attic. Most roofs are naturally black because of the bitumen or other chemicals. But if this is true for summer a dark roof can be a wonderful asset during cold maryland winters. The most common type is known as gloeocapsa magma also known as blue green algae.

The algae will worsen and become more noticeable each year trapping moisture and causing premature shingle aging and granule loss. A dark roof in the summertime can most definitely mean higher energy bills. During heat waves some of the most vulnerable people are those living on the top floor of a building with a black roof. Thanks to modern technology there are several dark colored metal roofs that have highly reflective pigment.

This algae growth usually begins as small spots and then eventually becomes visible streaks. The algae feed on the limestone in shingles. That s why you don t often see darker roofs in warmer climates. Ballasted black membranes can have similar performance to white membranes.

My biggest question is why are we still putting black roofs on our buildings. The black streaks running down roofs are actually a hardy algae called gloeocapsa magma. Vegetated green roofs can use black membranes because performance isn t affected by the membrane solar reflectance. Now this covers shingles built up typically called tar and gravel or bur modified bitumen and epdm.

The debate between white roofs versus black roofs has raged on for years however recent science has shown the reflectivity of white roofs has given them the edge. Although these dark spots and ugly black streaks on your roof may look like dirt mildew soot or mold what they really are is algae. List of the cons of black roof shingles. They absorb heat during the hot days making it hotter.

Built up membranes can be surfaced with energy star cap sheets creating a white membrane. If black is your preferred roof color you might think that a black metal roof would absorb more radiant heat since it is dark.