Some Thoughts on Reflective Roof Coatings

Posted on 10/19/2009

Green roofs have been a hot topic over the past few years, although there is little consensus as to what qualifies as a green roof. To some this means having a garden roof, for others it means using the roof as a solar energy platform, and to others it is the application of a reflective coating.
Reflective coatings are popular, largely because they are believed to save money on heating and cooling costs by eliminating solar heat gain. Money is saved by the application of a reflective coating, and most of the time to get the type of energy savings a reflective roof coating provides without having a green roof, a building would need to radically overhaul and upgrade its insulation which is usually more expensive than just applying a coating. From a financial standpoint, reflective roofs make a certain amount of sense.
That being said, the primary reason to get a reflective roof coating installed on your building has nothing to do with energy savings. The overwhelming bulk of scientific evidence shows that the world’s climate is changing, and while some may disagree on the cause of this global climate change, it is demonstrably happening everywhere.
Most of this climate change is attributed to the green house effect. Sunlight comes through our atmosphere, hits the planet and warms it, and then ostensibly that heat is radiated off the planet so that Earth stays at the nice habitable temperatures we’ve all come to enjoy and depend on. The green house effect prevents the heat gained by the sun from radiating back into space. Effectively, sunlight hits the Earth, warms the Earth, and then attempts to radiate back into space, but it cannot because the greenhouse gases trap the heat and redirect back towards the planet. This causes the Earth to get hotter and starts a cycle in which the average temperature of the Earth continues to rise and rise because excess heat cannot be vented off of the planet.
With a reflective roof coating, the sunlight hits the roof and instead of being absorbed, it is bounced back into space. The solar gain never really happens and the Earth doesn’t get any hotter because the heat is immediately redirected off world. Reflective roof coatings may save you money, but they will also help save the planet (or at least help to preserve it as it is now). Ultimately, while there is a financial reason for installing a roof coating, the real benefit is an environmental one and preventing a global catastrophe involving violent, cataclysmic environmental upheaval will always be cost effective.