As energy costs rise and climate change is talked about more, more and more people are looking for eco-friendly roofing options for their homes and buildings.
Among them, cool roofs and green roofs are growing in popularity.
Although both can be viable options for improving thermal efficiency and reducing reliance on energy for keeping buildings cooler, cool and green installations are very different.
Roofers stress the importance of understanding the pros and cons of each before investing in one.
All About Cool Roofs
A cool roof is one that is designed to be thermally efficient by preventing the passage of UV rays through the roofing and into the building by reflecting them off its surface.
What Are The Pros?
The biggest advantage to choosing a cool roof is that there are many types available and the reflective effect can be gained in various ways.
Materials that naturally reflect UV rays such as metal are popular, as are higher r-value asphalt shingles coated with reflective granules.
There are also reflective coatings that roofers can apply to many materials to make them cooler and increase their R-values to make them cooler, noting that white or lighter-colored materials are cooler than darker materials.
Most of these options cost the same or only slightly more than standard roofing products, making them the most popular choices for the environmentally conscious.
What Are The Cons?
There are only a few disadvantages to cool roofs, mainly based on where they are used.
Since cool roofs reflect UV rays, they are best used in hotter climates that do not get too cold in winter as heating and extra insulation are necessary to keep the space warm during the winter.
Yet cool roofs used in very hot climates can predispose the structure to moisture and mold problems, so the careful balancing of under-roof ventilation is necessary.
In addition, highly efficient metal roofing can also create glares that many may find unsightly.
All About Green Roofs
A green roof is one that is designed to be thermally efficient by preventing the passage of UV rays through the roofing and into the building by absorbing and holding that energy, then releasing it later after it gets cooler outside.
What Are The Pros?
Green roofs are available in two basic forms:
- Clay tiles and similar materials that absorb energy without releasing it into the structure
- Actual green living roofs on the tops of buildings.
Tile roofing made from organic materials like clay and cement are a sort of cool-green hybrid, as they can also be painted lighter in color or covered in a reflective glaze or paint, but living roofs simply absorb all that energy into itself and use it to promote vegetation growth.
Living green systems absorb carbon and release oxygen to clean the air and can also absorb rainfall, aiding in the prevention of flooding in urban areas.
These types of roofs can also be used to grow food, decorative plants and flowers, and more on rooftops while insulating the building and keeping the interior cooler in summer and warmer in winter.
What Are The Cons?
There are a number of valid disadvantages to green roofs that one should be aware of before planning one with a roofer.
Primarily, they are expensive to set up as living green roofing is a specialty treatment to use on the top of any building and ceramic tile is fairly expensive as well.
Living roofs and tile roofing are both exceptionally heavy as well and can only be installed on buildings that are structurally sound enough to support all the extra weight.
Leaking is another potential problem with living roofs, so thick membranes must be used to prevent it.
Does A Cool Or Green Roof Sound Good?
Saving energy with a thermal-efficient roof is an important choice that any home or building owner can make as we all try to do our part to combat climate change.
Which one you choose will depend on many factors, from the type of building where it will be installed to what the amount of your budget.
Discuss the options with an experienced roofer today to make the best choice for you!
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