What’s the most energy efficient system in the commercial roofing industry? The answer could be a lot greener (and softer) than you’d imagine. In today’s discussion, we’re going to dig deep into the the strange, yet gorgeous world of green roofing systems.
If you’ve been hunting for ways to cut down on daily operating costs and energy expenses, be sure to read along as we explore. These premium commercial systems may come in all shapes and sizes, but they are renowned for their cool roof capabilities. They also produce several awesome benefits for the environment.
What is Green Roofing?
Put simply, green roofing incorporates man made soil and natural plant life to produce a powerful barrier against the elements. Most green roofing systems incorporate five or six layers designed to support the surface flora while protecting the base underneath.
The Layers of a Green Roofing System
- Plant Life (Top Layer)
- Growth Medium
- Filtering Cloth
- Drainage Layer
- Root Shield
- Waterproofing Membrane (Bottom)
Some living roofs also incorporate additional insulation, reducing heat gain during peak solar hours. The top two layers comprise the floral ecosystem. Pest-free, nutrient-rich growing medium sustains the plants over the years. Plant choice varies based on the scope of the project. We’ll expand upon in a little while.
The filter cloth prevents soil from escaping downward, while still allowing moisture to travel through the underlying drainage layer. Next, a tough barrier prevents roots from penetrating the underlying roof decking and damaging the building structure. Finally, the waterproofing diverts any excess water towards the outside of the structure, where it can drain safely.
Most of these naturally cool roofing systems fall into one of two categories: deep intensive rooftops and shallower extensive roofs. Both provide the famous efficiency and air-cleaning capabilities that green roofing systems are famous for, though the scope and maintenance requirements vary greatly! Let’s break down the differences between the two.
Extensive Green Roofing Systems
While popular among rural homes, extensive green roofs have also found a rising market among business owners. These smaller roofing units incorporate a much smaller layer of growing medium, one of the primary contributing factors to the system’s overall dead weight. With less supporting feux-soil, extensive roofs support very small shrubs, flowers, grasses, and sedums.
According to a study performed by the General Services Administration (GSA), extensive green roofing systems average $10.30 to $12.50 per square foot. That includes the price of installation, though maintenance costs may lift that average a little higher. Upkeeping requirements for these smaller roofing systems are much lighter compared to those of intensive garden rooftops. Speaking of…
Intensive Green Roofs
If you’ve ever wanted your own garden patio, but lacked the commercial real estate to make it happen, an intensive system could be perfect for your business! These cool roofing solutions incorporate a much larger layer of growing medium (6+ inches), capable of feeding larger bushes and even trees. Of course, this produces a more significant weight per square foot. Many commercial properties require additional structural support as a result.
Intensive systems can be landscaped just like any garden. Many companies like to create an outdoor cafe space or even a full-size restaurant. Others confine their plant life to sections of the rooftop using a modular design.
Is Green Roofing Energy Efficient?
Green roofing systems certainly aren’t your typical cool rooftop solution. After all, most cool roofs utilize a reflective surface to divert sunlight away from the structure. The resulting coolness stops heat gain in its tracks.
But green roofs are…well, green.
They don’t reflect light the way a PVC roof (for instance) would. As we mentioned in our recent blog on cool roofing, the plant life in living roofs fight against heat by releasing moisture into the surrounding air. This process is called transpiration. While we don’t have time to go into the science behind it, transpiration produces a remarkably cooler environment that protects the underlying structure from expensive heat gain.
In as few as six years, the energy savings produced by green roofing systems catch up to the investment costs! Considering impressive lifespan of 50 years that many of these roofs enjoy, that’s decades of savings available to businesses. Of course, there are even more benefits to take advantage of.
Additional Perks of Going Green
Plant life naturally absorbs a lot of storm water. In green roofing systems, this means that the bushes, grasses, trees, etc. greatly reduce the amount of water runoff during periods of heavy rainfall. This makes “going green” a very attractive option for environments with long storm seasons. According to the GSA, green roofing systems can reduce stormwater runoff by as much as 65%! This makes it much easier to manage drainage around your commercial property.
As you probably know, plants play a special role in purifying our environment. By absorbing natural and certain man made toxins in the air, green roofing systems can greatly reduce their harmful effects. If your business operates in a heavily industrial metropolitan area, a green roof is one way to fight against the unpleasant pollution that so many struggle with.
LEED Certification and Local Tax Benefits
LEED certification is a grand goal that thousands of companies strive for every years. Creating an energy-efficient, low-impact structure is no easy task. Green roofing systems can bring businesses much closer to the exacting standards of LEED certification by reducing daily energy consumption.
Key Considerations for Green Roofs
As mentioned before, green roofing systems come with substantial weight requirements, especially with intensive designs. That means that commercial buildings often need to structural reinforcement to sustain the additional load. Green roofs also feature a significantly higher cost per square foot than other commercial systems, with per square foot costs reaching as higher as $25. The long lifespan, relatively low maintenance costs, and high energy savings however go a long way towards making these living roofs a very attractive solution.
Want More Information?
Green roofing systems offer so many benefits, but their intrinsic beauty is reward enough for many. To find out more about the energy saving capabilities, costing, and requirements of green rooftops, talk with one of the many contractors in the Roofer’s Guild Directory! Our seasoned experts offer dependable knowledge and skills for all your commercial roofing needs.
You can also start your search by calling us directly at (877) 282-8968. We can’t wait to serve you!