What Is Green Roofing?
Curious About Green Roofing For Your Commercial Property? Learn More About It In Our In Depth Guide.
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Green Roof Overview
A green roof is also commonly referred to as a living roof and is usually on a structure or building covered almost entirely with vegetation. This vegetation is planted on a waterproofing membrane. However, there may be a few additional layers, like a root barrier, one for irrigation and the other for drainage.
Most green roofing projects use potted plants, but they aren’t considered true green roofs; it’s still hotly debated. However, another addition is rooftop ponds, which many of the newer green roofs have and are mainly there to treat grey water.
So, are green roofs worth the effort and money spent to build them? In this article, we’ll examine how green roof technology works, and why you’d want to consider it.
What’s The Purpose of A Green Roof?
A green roof may serve several purposes, like absorbing water and offering an additional layer of insulation. Plus, it helps contribute to the environment by serving as a place for wildlife, producing oxygen, and decreasing stress for people around it, thanks to the addition of an aesthetically pleasing landscape. However, it can also lower urban air temperatures while mitigating what’s commonly referred to as the urban heat island effect.
Green roofs are often a no-brainer for redevelopment and retrofitting projects. However, there are also now popular amongst new buildings, and many are installing them on large industrial and municipal buildings. One reason for their popularity is that they use the natural functions of plants that effectively filter the water and treat suburban and urban air.
Types of Green Roofing Systems
Generally speaking, there are two types of green roofing. You have the extensive green roof and intensive types, which are distinguished by the amount of vegetation used. Extensive green roofs can support up to 25 pounds of vegetation for every square foot of space. However, intensive can hold around 150 pounds per square foot. Both are equally effective at combating urban heat islands.
Each type of green roof requires a different amount of labor to maintain. Intensive green roofs take a lot more work to manage and mainly require keeping every kind of plant separate to maintain a garden-like look and feel.
Extensive green roofs, or extensive roofs as they are called, on the other hand, can grow without restriction. However, nature dictates. In other words, they can take care of themselves. The only maintenance they will require is annual fertilization and weeding.
Private homeowners choosing the intensive type of green roof systems can decide which flowers they want, essentially allowing them to sculpt the space they always wanted.
On the other hand, extensive green roofs are designed to be maintained annually, which means they can grow more naturally. Sometimes they may become overgrown, at which point they receive a bit of maintenance. If anything, this makes navigating these types of roofs harder because an individual can’t just walk through all the greenery enjoying the sights it offers. That’s why a green roof project needs to be carefully planned.
However, both types of green roofs use a layered system, establishing a base for those planting the greenery to use the soil and other materials they would need to maintain the plants while at the same time removing all wasteful byproducts. The several layers mimic a soil profile, creating natural drainage which allows liquids to filter through while nourishing plants.
Recent advancements in green roof mitigation technologies and studies have yielded a new form of green roofing, referred to as comprehensive roofing. The format is meant to support a broad variety of plants similar to intensive green roofs while permitting dense vegetation similar to an extensive roof. This makes this new green roof system the ideal choice for building owners that want to enjoy the best of both worlds.
What Does A Green Roof Cost?
The cost of installing a green roof varies. It all depends on the type and size of the roof. For instance, an extensive roof that does not have public access can cost one-tenth to a third to build compared to an intensive green roof with public access.
Usually, the initial cost when you install green roofs is higher than a roof with conventional materials. Still, building owners can often offset these cost differences by reduced energy costs, storm water management fees, and the excellent lifespan that green roofs offer compared to a conventional roof. Plus it has a drastic effect on the building’s heating and cooling costs.
Typical green roof maintenance includes weed control, fertilization, replanting, and irrigation. However, intensive green roofs will require a higher degree of maintenance in order to maintain a higher degree of aesthetic appeal for the public.
A study conducted at the Lawrence Berkely National Laboratory across green roofs, cool and conventional roofing found that while green roofs were initially more expensive compared to others, they provided more benefits for every square foot across 50 years. These benefits included reducing storm water fees, improving energy savings, and reducing emissions. In terms of dollar value, extensive green roofs are $14 more beneficial for every square foot covered, while cool roofs provide $2 in terms of benefits for every square foot, compared to conventional roofs.
Are Green Roofs Better Than Cool Roofs?
Cool roofs are often seen as an alternative to Green Roofs because they, too, can reduce the heat island effect. These roofs are made from emissive and reflective materials that help homes remain cooler during the hot weather.
On the other hand, green roofs have an initially higher cost than cool roofs, but they last exponentially longer. This translates to savings in the long term.
Both green and cool roofs help to lower surface and air temperatures while decreasing the demand for energy within the structure. But with cool roofs the benefits beyond this, according to the Environmental Protection Agency, such as their ability to absorb pollutants, and carbon dioxide, ensure a natural habitat. Intensive green roofs serve as an ideal recreational green space. These are best suited for projects with limited budgets, focusing on energy savings.
Green roofing is one of the best choices for anyone that can afford the initial upward cost. Not only does it provide you with green space, but there are environmental benefits associated with it.
We Service The Entire Denver Metro Area And Beyond
Maxx Roof LLC serves the Denver metro area and the surrounding areas. Some of the cities we serve are Denver, Lakewood, Castle Rock, Arvada, Aurora, Boulder, Broomfield, Littleton, Englewood, Centennial, Parker, Thornton, Wheat Ridge, Golden, Morrison, Brighton, Commerce City, Watkins, Highlands Ranch, Lone Tree, Edgewater & beyond.
If your home or commercial property is located anywhere throughout the greater Denver metro area, give us a call for a free inspection & estimate. When you choose to work with Maxx Roof LLC, your are choosing to work with a roofing contractor you can count on, every step of the way.