What Are White Roofs?
What Are The Advantages Of White Commercial Roofs?
White roofs are cool, as in they stay cool and help promote cooler building interiors. This is due to their enhanced solar reflectance and thermal emittance, so they are less affected by the presence of sunlight. With less energy conducted into and around the building, it’s easier to maintain comfortable temperatures inside, but that’s only the start. Here are some other reasons why commercial building owners are rapidly opting for white roofs:
- Promotes heat safety in hotter climates – On a bright summer day, the difference in temperature between a white roof and a dark roof can be as much as 80 degrees Fahrenheit. Much of that extra thermal energy is conducted into the building, making conditions uncomfortable, especially for people sensitive to the heat. According to The White Roof Project, a white roof can reduce interior temperatures by 30 degrees or more, making it much easier to keep temps in the safe zone.
- Reduces energy costs – In warmer climates, a white roof can greatly reduce the load on a commercial HVAC system, and therefore reduce cooling costs. Studies comparing white and dark roofs have noted close to a 20 percent reduction in energy spent cooling, as long as a white roof is overhead.
- Reduces emissions – Not only are energy costs reduced, but emissions are as well. This includes a reduction in carbon dioxide emissions, so installing a white roof is an easy way to go green.
- Mitigates the effect of urban heat islands – Urban heat islands (UHIs) occur inside and around urban areas and are pockets of elevated temperatures caused by human activity. UHIs are particularly noticeable at night, where the difference between urban and nearby rural areas can be as high as 20 degrees or more. During the day, the relative impact of UHIs are less, but even a small increase in temperatures can be enough to cause heat-related stresses and illness. Since white roofs reflect and emit more solar energy, they can reduce the spread and intensity of UHIs.
These benefits are considerable, and even better, commercial building owners can install a white roof without replacing their existing roof.
If a building owner wants a white roof, does the existing roof need to be replaced?
Roof replacement is expensive, disruptive and sends a lot of waste to the landfill. Fortunately, even when a roof is in obvious need of repair, it may still be a candidate for renovation instead of replacement. It’s during renovation, not just replacement, that building owners get the white roof that they’re looking for.
Some roofing experts utilize fluid-applied systems that provide a complete seal against the elements. During renovation, a non-permeable membrane is installed that provides protection against hurricane-force winds, monsoon rains and intense UV radiation. This membrane can be easily replaced every 15 to 25 years and is an extremely effective way to prolong the life of your building’s roof. The fluid coating is white in color and several layers are applied to ensure maximum protection and solar reflectance. It can also be applied to a variety of roof systems, including BUR, metal, foam, single-ply and modified designs.
Renovation, if possible, is usually preferred over roof replacement for a few reasons, including:
- Much less expensive – In most cases, renovating a roof costs 50 percent less (or more) than replacing it.
- Much less disruptive – Replacing a roof is hard work and requires a lot of manpower and machinery to pull off. That means constant foot and vehicle traffic around the building, and all the noise that comes with it. Roof replacement also requires a lot of odor-producing materials, which can be difficult for people inside the building to deal with. Renovating a roof, by contrast, can be done with far less noise and odor.
- Extended warranty options – If you’re working with a reputable roofing company, they will provide a warranty for any renovation work. The fluid-applied systems used during renovation are extremely reliable, which is why some companies offer up to a 25-year warranty for their work.
- Reduces landfill waste – Premature replacement produces tons of unnecessary waste each year, but a renovation reduces this waste.
How do I know if it’s time to renovate a commercial roof?
Prior to renovation, it’s important that the building’s roof be inspected by a professional, as not all roofs can be renovated. Every roof is also different in terms of condition, and additional work may be required before renovation can begin. A roof renovation expert should be able to provide the following:
- A comprehensive inspection of the roof’s condition, using several technologies to note where potential roof defects and water intrusion may exist. Roofing teams have several tools in this regard, including core samples, commercial moisture meters and infrared thermography. One or more of these tools may be used to determine where the existing roof will require repair before renovation can begin.
- Pressure washing and debris removal. Cleaning the roof is essential to a safe workspace and effective repairs, so it should be standard with renovation.
- Removal of old repairs and materials. It’s likely that outdated repairs and worn materials will be present on any roof requiring renovation. A professional roofing team should be able to identify these and remove them prior to renovation.
- Insulation replacement. Once water penetrates the building, it will quickly saturate insulation and reduce its effectiveness. In fact, during infrared thermography, it is this saturated insulation that usually shows up on thermal imaging, due to its inability to provide a heat barrier. Before renovating, a reputable expert will pull this insulation out and replace it with new material.
- Drain, flashing, scupper, joint, duct, seam, lap, penetration, and corner repair. These are responsible for keeping water out of the gaps between roof components like HVAC systems, skylights, vents and the like. If they aren’t in good condition, they will still allow water to intrude, even after renovation. For this reason, a professional roofer should be ready to handle anything that is damaged or incompatible with renovation.
While it is recommended that commercial building owners have their roofs inspected at least twice a year, make sure you choose a reputable roofing company that focuses on renovation over replacement. If during inspection, renovation is the recommendation, then consider what a white roof can do to keep temperatures, and your energy costs down.