In my opinion as the Green Roof Patroller, the best green roof solution can only come from well-educated practitioners with a very long experience in selected horticultural and landscaping fields. Over the many decades, Green Roofs have been developed from a mixture of high performance natural materials to a combination of engineered elements with natural components.
Something that may have been tested by NASA or firefighters isn’t automatically good for the plants or the environment. The engineers or technicians behind such reinventions of the wheel might have fancy degrees. However, many have hardly installed their own developments with their own hands on a large scale.
Long Term Research Lacking
Additionally, they never evaluated their inventions or innovation over a long enough time (more than 5 or 10 years) before making them available for the market. I have seen people coming into this industry with a big bang and quietly leaving after a while to move up in the hierarchy of a different industry – to do the same there?
Who You Gonna Call?
Erosion Blanket – is eroded and takes the soil down. Sometimes a belt, suspenders, duct tape, super glue, and a nail in the belly button don’t help to hold the pants. Buy pants in your size!
All of a sudden, the kid falls into the water well (a/k/a the Green Roof is not performing), then the building owners call for practitioners who are supposed to fix the engineers’ problems. Building owners don’t usually call the original engineers or technicians because they can be vain.
And, when later problems or questions arise from the building owner, the engineers behind the design of the green roof don’t necessarily feel responsible anymore. Perhaps they don’t always know the answers without Google, and these are hardly right. In some cases they call a practitioner later; and even then, they don’t always provide the entire picture.
The beauty of engineering – a squared box doesn’t follow a radius.
Engineers are typically not seeking for answers that discredit their efforts. However, they try to suck out every piece of information they can get from practitioners and simultaneously avoid valuing the source because of being afraid of scratches to their polished image.
Plants vs. the Bottom Line
An additional problem is that most engineers (even at universities) are on the payroll of large corporations that are pressured to develop profit-maximizing solutions. These solutions are typically against the needs of plants – because plants don’t care about money and the stock market.
Plants are “only” the key player on green roofs. No happy plants = no Green Roof = no happy client.
Underperforming Green Roofs
I estimate that around 50%-60% of all Green Roofs in North America are underperforming, failing, or have been renovated, replaced, or will be going under a major renovation soon. For Germany I would estimate this number at around 5%. At the same time, in Europe an extensive Green Roof costs around $5/sf and in the US closer to $20/sf.
My Concerns within the North American Green Roof Industry Besides the Odd Engineering Practices?
Ingenuity – when polystyrene plastic materials fall apart before they are installed.
1. No solid, full time practical training over more than two years before getting a professional in this field.
2. Students are not being paid during practical education – they actually have to pay a few 1,000 bucks to get a certification, like buying a certificate or a title at Walmart.
3. No innovative and large scale research over 5-10 years. Just baby step copies and mail stamp-size research (typical research areas in Europe are 10-50 times bigger than in the US).
4. Green Roof contracts are coupled with roofing contracts (it is like buying a dryer only in combination with a fridge).
5. Low roofing quality, materials and/or inverted roof membrane assemblies (IRMA).
6. Repurposing materials that were never engineered for green roofs (e.g., in my opinion, there is no American-made drainage board that would meet my criteria and the full needs for plants).
7. Worthless single source warranties. If you choose your own microwave, you don’t get a warranty on the fridge.
8. Greed for quick cash and/or fame.
9. Not understanding the big difference within the horticultural trades (a carrot grower is not automatically a green roof expert and a beekeeper doesn’t understands all plants).
10. Huge deficit in experienced and reliable hands-on installers and maintenance for Green Roofs.
11. Often, hands-on installers/practitioners are treated dismissively from architects, GCs (general contractors), roofing companies, or engineers.
This makes a worried customer and a happy landfill.
Green Collar Workers
Practitioners are not Blue Collar workers, they are not White Collar workers. We are Green Collar workers who stand above the traditional collar thinking and who have had the patience to monitor this unique living environment for decades to learn how to go beyond what is written in books or on the internet.
All the above problems have a great potential to damage the Green Roof business in the long term. Building owners don’t want to be ripped off and each project that causes problems will change their opinion about Green Roofs in general. While many building owners don’t want to commit to owning up to a problem on their green roof, others will spread the word among other building owners.