Environmentally Friendly Commercial Construction sounds like a complete contradiction, doesn’t it? Buildings are made of concrete and glass, burn loads of energy for lighting, heat and cooling, and suck up an enormous amount of heat from the sun. One way to offset some of that heat is to incorporate an environmentally friendly vegetative roof.
How can plants grow on the top of a building’s roof, using foam products? How can it be considered environmentally safe? It’s not as far-fetched of an idea as you might think. EPS, or Expanded Poly Styrene foam is non-toxic, recyclable and is used in many different commercial applications.
While the term ”Green” is such a broad spectrum term, vegetative rooftop design is far more “Green” than a flat roof painted white to mitigate heat. Deflecting the heat of the sun will save on cooling costs, but it is misleading turn of phrase in this writer’s opinion. Instead, let’s refer to it as vegetative roof design.
Architectural projects are getting “greener” all the time. One of the products that has found its way into commercial construction projects is Expanded Polystyrene Foam (Geofoam or EPS foam). In this particular application, Geofoam is used as an insulator, as well as the bedding of rooftop gardens. Geofoam is much lighter than soil, so having a layer of Geofoam as the bed of the rooftop not only saves on structural load bearing limitations, it also provides insulation qualities that keep the building cooler.
As you can see from the image above, beautiful things can be created by utilizing science and engineering, as well as nature’s horticulture. A natural insulator, Geofoam can be used in a variety of ways to act as the foundation of a rooftop garden, and it doesn’t have to be flat and unimaginative. Because of its ease of use, it’s light weight and recyclability, this non-toxic element of construction is without question a boon to the commercial architecture and construction fields.
Vegetative Rooftops and History
Although incorporating vegetative roof design into commercial projects is a relatively new (Germany-1970’s) design element, they have been with us for centuries in one form or another. Sod roofs, as seen in the photo below, have been popular in European countries since the early 11th century, if not further back. Dried vegetation is another means by which our ancestors have insulated and weatherproofed their homes, which again, have been around for hundreds of years.
Implementing live plants on commercial buildings with the specific goals of heat mitigation and esthetic deign began in Europe and made its way to the United States as far back as the 1970-s. Its popularity and usefulness has just recently made it a “value added” style of roofing construction.
Blending Nature with Science and Engineering
When incorporating a vegetative roof into an architectural plan, it takes more than just including it in the overall scheme. Engineers must determine the overall depth requirement of soils, weight of materials, number and types of plants, as well as the overall vegetative design plan. By engineering various sizes and shapes of Geofoam, the garden can take on a topical design that is only limited to the designer’s imagination, and of course, budget.
Slopes, rises, run-off grading, crowns for drainage points and height variations can all be input into the design, as Geofoam can be shaped into any form. Geofoam can come in sizes suitable to the desired insulative depth, from 2-4 inches (R value), and as large as 8’ by 4’ by 3’ blocks, which can be shaped as desired. Best of all, Geofoam is environmentally friendly.
Here’s a cross-section example:
GeoFoam and the Heat Island Effect
Urban areas such as the business centers of major cities often suffer what is known as heat island effect. Due to the significant amount of concrete and glass, the heat of the sun literally bakes into the inorganic materials, often holding and then dispersing said heat through the course of the day and night. Mitigating the effects of heat islands has been on the minds of both conservationists and engineers alike.
White roof design initially mitigates the heat, but over time that mitigation capability deteriorates, while vegetative roof design continues to perform. By ensuring the proper design elements are incorporated, the use of Geofoam as the insulating material goes a long way toward that end. Geofoam is so lightweight it does not contribute to the stress load of the roof, and is impervious to water damage/rot, heat shrinkage, is non-toxic and affordable.
Just One of Many Uses
Geofoam is a versatile product that use in vegetative roof design is one of many applications. At present, Polyfoam supplies architects and engineers a variety of Geofoam products for use in road construction, packaging, residential and commercial exterior construction, and many custom applications . For more information and a free consultation on how Polymolding and Geofoam can make your next project a success, feel free to contact us.