The Sky is Falling: A Critique of Failed Sloped Extensive Green Roofs

2011-09-08T07:50:00.000-07:00

Tuesday, September 06, 2011

By Jorg Breuning

As of late we have been receiving more and more calls from building owners in distress about their green roofs. The most serious of these complaints being erosion problems on their sloped roofs. Sloped green roofs are a bit more complicated to design, install, and maintain than flat roofs and as a result people who disregard or don't know of the established FLL guidelines for sloped roofs, have created dangerous and costly situations ranging from mudslides to roof collapse.

One of the most infamous of these rooftop blunders was last winter in St. Charles, Illinois. The project was designed to be the largest sloped roof in the US and during a heavy snow storm the roof collapsed. Fortunately no one was hurt however the damage was devastating.

Why did the roof collapse? The problem lies in the drainage. Snow is frozen water and where you have more water accumulating on a roof you will also have greater amounts of snow accumulate. This insufficient or clogged drainage system and poor growing media is the most likely culprit in areas that held water or snow. All this added weight during an extreme winter put the roof way beyond its capacity.

Sadly, this situation and others like it could have been avoid simply by hiring a true expert and checking their performance history for similar projects. To read more about the dangers of improperly design sloped extensive green roofs and how to avoid them click here.

Combining PV and Green Roofs

2011-08-18T08:27:00.000-07:00

In Europe there are many manufactures with PV and green roof solutions. I also like to mention Optigreen AG - probably the larges green roof manufacturer in the world -for sure the most flexible system in each regard. I did my first Green roof- PV project in 1995 Zeppelin Carré Stuttgart.

My company is an American company but I am still involved in projects in Germany or featuring German projects from the past or ongoing. Last Friday I visited the construction of the largest green roof and PV combination project in the world. This 75,000 sft PV Green roof combination is in Stuttgart Germany, will produce energy for 250 four person house holds and -as said still- under construction. However the entire development of this new fair ground as the forth largest PV park in the world mounted on roofs. There are endless green roofs and PVs. With Roof mounted PVs Germany has nearly 20 projects under the largest 30 in the world and has the leadership in the world.

See a 2009 rendering of the Green roof PV project and expect more information. /jbi

Green Roof Service

The Sky is Falling: A Critique of Failed Sloped Extensive Green Roofs

Combining PV and Green Roofs