Florida Green Roofs and Hurricanes, Storm Season is Fast Approaching

The Eastern Pacific Hurricane season begins soon and the Atlantic Hurricane season follows shortly thereafter.

Routine green roof maintenance and hurricane inspections are important for Florida Green Roofs

Hurricane design is an important consideration for green roofs.  If a green roof is to be built in areas subject to hurricane or cyclone impacts then a few simple guidelines will help make the design more resilient against wind and storm damage.

At a minimum, we recommend;

1. No large trees on a roof.
1. Small shrubs and small trees may be used successfully depending upon the final design.  This may seem like a common-sense guideline but people try to put all types of tall, large trees on patio or garden roofs.  During a 130 mph cyclone, the tree may be blown over and may cause damage from the fall against the structure or to the street below.  It may also become airborne if the winds are strong enough.  Growing up in Hialeah I saw plenty of hurricanes come through our area and witnessed first hand the power of these storm events.
2. Anything and everything on a roof should be permanently attached.  
1. Walkways should be constructed from a permanently attached TPO, EDPM or other mat and permanently affixed to the roof.
2. No loose chairs, tables or other items should be present.  If you wish to have a chair and table stay on a roof during a cyclone, they must be permanently attached.
3. All green roof components must be permanently attached to the structure.
4. Any trays, plastics, pots, containers or other green roof components must be permanently attached to the building structure.  Florida Building Code does not allow for loose items to be installed on a roof - they must be attached.
5. Green Roof Irrigation components must be permanently attached to the roof.
3. Make sure all tools and gardening utensils are picked up and put away.
1. It is very easy to forget the pair of shears, scissors or pliers on a roof.  Remember what you were using and where you liad them.
4. Plant selection should be focused on those species that have historically survived cyclone and hurricane incidents.  There are several good books available at most bookstores here in Florida on proper cyclone resistent landscaping and many resources on the web, such as the Brevard County Landscaping Guide for Hurricane Areas.
5. Check on the NOAA National Hurricane Center website daily.  The NHC webpage is a wonderful resource, full of links to climatic data.

Always use a green roof design or green roof system already proven in actual field trials with hurricane simulation testing.  Watching a green roof blow off during a storm is an avoidable event.  Due diligence upfront and preparedness is important for green roofs in hurricane prone and cyclone impacted areas.

Green Roof Weeds, Maintenance and Taking Care of Plants on the Roof

This is an update of a post I wrote about two years ago.

I was asked to contribute towards a new municipality green roof regulatory policy, one where there was considerable incentive given developers towards site entitlements if the project would include a green/vegetated roof.

One of the committee members also invited was an accomplished technical/construction specialist - one with multiple graduate degrees in technical and mechanical fields.  But she did not understand plants.

Her past green roof projects had been designed around available landscape plants.  Choose the typical on-the-ground landscape plant and design irrigation and fertilizer and other accessory design criteria to support the landscape plants - was the motto.

Whenever we'd discuss native species or volunteer species showing up on the roof, she'd immediately try to quash the discussion by shouting 'WEEDS!  NO ONE WANTS WEEDS ON THE ROOF!'

I think it was because she felt uncomfortable trying to work with the organic, dynamic complexities of nature.  Obviously she wanted no part of having native wildflowers or grasses on the roof.  Moreover, I've seen some of her 'landscaped' green roofs and they quickly revert back to natives, or as she calls them 'weeds'.  I am sure the selective herbicides are used quite often.

We must stop seeing masses of green and train ourselves to look at the plant.  There are few if any true weeds in nature and on green roofs.

Each plant has its own beauty and purpose, even those obnoxious ones.

I've often quoted Lydia Cabrera in saying "there are more spirits in the plants/forests than in the sky'.

The vegetated roof in Sanford I toured this week was full and vibrant due to volunteer plants.

There are no weeds.

I learned this from my daughter, today.  Though I knew it long ago.

She showed me her photos of one of the most obnoxious plants in my book - Bidens alba (Hairy Beggar's-tick).  Just try walking through a mass of Bidens and wait till you come out the other end of the patch....

I love their masses of white flowers but distrust their desire to bestow me with masses of aggravating seeds.

I almost at this time of the year agreed with the self-centered technocrat who probably couldn't tell bamboo from horsetail or coral honeysuckle from trumpet vine.  I almost shouted WEEDS!

But Jincy showed me her pictures from today.  Ones she and Ruairi took out back.  The Bidens are growing on the roof too.

And Lydia Cabrera is right about more spirits in plants.  And I am right about 'there really are no weeds'....

No need to weed green roofs.  Just step back and admire the Bidens.

Green Roof Beauty - Not Weeds - Bidens alba providing habitat and foraging

Green Roof Wonders - Not weeds, Bidens alba provides nectar

Happy Green Roofing!

Kevin

Did your Green Roof Turn Out To Be Something You Didn't Expect?

Don't laugh just yet - I hear this comment often!  And its true, vegetated roofs have a mind of their own.  But today I am writing because I was meeting with one of the professors at one of the universities last week.  We were discussing a stormwater research project.  Near the end of the meeting the conversation turned to the many BMPs referred to in the proposed new Florida stormwater rule, one being Green Roofs.

The professor, with humor in his/her voice, spoke of the green roof project the university architect designed and how after installation the roof looked beautiful.

Continuing, the professor added that the roof had changed so much over the past year that most associated with the project were shocked.

I've seen this occur on every vegetated roof here in the Southeast US.  The maxim is:  Unless you have an endless budget for maintenance and unlimited time to work with the roof, expect change.

Through design you can minimize the change but you should still expect change.

The winds, rain and birds bring seed material.  New aggressive pioneer species pop up right and left.  The harsh environment knocks back the carefully tended to plants installed during the initial planting.  Harsh winds desiccate some of the plants.   Others wilt or develop dampening off with the high heat and humidity.  A vegetated roof generally has a mind of its own and you must ask if you have the time and energy to fight.

Again, I remind all I am speaking from a Florida and humid Southeastern US perspective.  Green roofs may behave different up north, I do not know.

So, I smile when I hear someone say, usually while shaking their head, that a vegetated roof has turned into something they did not expect.

We are compiling a database of plants suited for Southeastern US roofs and will be posting before the end of the year - would love your feedback.

Happy Green Roofing!

Kevin