Innovations in Environmental Roof Systems


Flat commercial roofs are increasingly being turned into usable space. Solar (photovoltaic) and vegetative roofing systems, as well as a newer trend – “blue” roofs – are gaining in this area. One thing they all have in common: they all need a reliable waterproofing membrane between them and the building below. Let’s take a closer look.

Solar. Commercial rooftop solar systems have been around for years. Prevalent in the south and west because of more abundant sunshine, solar arrays can now be found in all areas of the US. Much of this trend is being driven by a concept known as grid parity. That’s when an unconventional energy source, such as solar or wind, can generate electricity at a cost comparable to that of buying it from the grid. So, commercial building owners who want to be “green” in areas with grid parity can install rooftop solar systems cost-effectively.

Solar systems are installed on the roof in one of two ways, each with its own challenges. Attached racking systems enable more flexible mounting with respect to sun positioning, but the roof penetrations required increase the potential for leaks. Ballasted systems avoid penetrations but are heavier.

Vegetative. Also known as “green roofs” in some markets, these are increasingly popular, especially on facilities in urban settings. They help make a building more energy-efficient, provide sound insulation, manage stormwater runoff, and can turn an unused rooftop into a space that benefits the owner, occupants, and the entire community. There are basically two types of veggie roofs:

  • Extensive vegetative roofs have shallow soil with plants referred to as “sedum” – low-growing, hardy, ground cover types. They require minimal maintenance.
  • Intensive rooftop systems are landscape-like and can provide attractive and walkable spaces. The soil is deep to accommodate a variety of plants and even trees. Intensive systems need regular upkeep and maintenance.

Blue. More formally known as controlled flow roof drain systems, these rooftop apparatuses are engineered to collect and store rainwater, then release it in a controlled manner. Blue roofs are gaining traction in urban environments where the controlled water release helps prevent water from collecting on the roof and mitigates sewer drain flooding, similar to traditional storm water ponds. Some more elaborate blue water systems use integrated technology to water rooftop vegetative roofs.

Regardless of whether you’re in the market for an environmental upgrade to your commercial roof, Tusing Builders and Roofing Services would welcome the opportunity to discuss your situation with you. Please contact us at your convenience.