More and more businesses, apartment owners, and homeowners are looking to create green spaces throughout their properties, including on their roof. There are many reasons why owners are regarding this as a good long-term investment opportunity. In addition to raising the value of their properties, they are also offering value to the surrounding environment.
What is a green roof?
The United States Environmental Protection Agency defines a green roof as follows,
“A green roof, or rooftop garden, is a vegetative layer grown on a rooftop. Green roofs provide shade and remove heat from the air through evapotranspiration, reducing temperatures of the roof surface and the surrounding air.”
Some also define a green roof as one that has garden elements where seating and other park elements such as benches, picnic tables, and pathways are available. That way, in addition to being an environmentally friendly installation, the space is also an extension for the building’s living and casual recreation spaces. This is of particular interest to apartment building owners with properties surrounded by concrete.
Is it difficult to create a green roof?
According to National Geographic,
“Waterproof membranes now make it easier to design green-roof systems that capture water for irrigation, allow drainage, support the growing medium, and resist the invasion of roots.”
Therefore, and experienced do-it-yourselfer could tackle this project over the course of several weekends. However, for those who are not comfortable with working on these types of projects, hiring a contractor is another option.
Roofing companies geared specifically toward the creation and development of green roofing are popping up everywhere. Just as someone would interview and request a portfolio from traditional roofing contractors, the same care should be taken when selecting a company to install a green roof. Property owners should interview and gather estimates from at least three contractors, evaluate the projected work, contact references, and scrutinize portfolios prior to making a final hiring decision.
Why are some owners uncertain about green roofing?
Green roofs date back to when sod and thatch roofing was a popular material to build roofs. Yet despite that history, property owners are still hesitant about installing one. Certainly reports like this one in Scientific American do little to encourage property owners. This article reveals that the green roofing used in Manhattan, New York leaves little to be desired and is in need of some serious reexamination.
According to the reporter, Amy Kraft,
“Rooftop gardens have the potential of lowering energy usage for heating and air-conditioning as well as reducing rainwater runoff, but their effectiveness is not well established.”
The problem lies in that the wrong plants are being used, so they are not holding up to high winds and the penetrating sun found on many city rooftops.
Do the research
The bottom line is, before making any type of large-scale decision such as a green roof, do the research. Talk to others who have a green roof to address all the pro’s and con’s of the finished project. When talking to the contractor’s references, ask them what they would have done to change anything about the project. Additional research includes learning what the best plants are for the structure’s area, how much material should be used on the roof, and how much maintenance is required when the green roof is complete.
As someone that works in the green roof industry I would never suggest a DIYer do their own green roof installation. The added weight of a green roof system is not something the original designer accounted for while designing the structure. This could lead to structural failure of the building.