Saturday, March 29, 2014

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.

Sunday, March 23, 2014

Florida Green Roofs and Biomimicry, Agavaceae and Dew

Nature offers the finest examples for us to look to when resolving green roof, or any other for that matter, issues.  Today I want to mention plants that catch air moisture, such as dew, and help 'irrigate' a green roof.  Let's look at some of my favorite green roof plants, Yucca and Agaves.
Floria extensive, sloped green roof
Green Roof Plants, Yucca and Agaves - note the hairs and clover, a nitrogen fixer
Yuccas and Agaves, with hairs across the surface edges of her leaves is a highly efficient fog and dew catching plant.

Likewise, with waxy, tough leaves and CAM (Crassulacean Acid Mechanism) photosynthesis, they can serve as the perfect green roof edge wind-break perimeter plant.

Yucca and Agave biomimicry tells us high dew catcher surface area to air mass contact is most efficient for air water vapor to occur. 

Many yuccas and agaves thrive in hot, dry, windy areas and make excellent choices for green roof plants.

Yucca filamentosa, Adam's needle is a favorite green roof plant of mine, reliably hardy in the freezing cold temperatures, evergreen, very drought tolerant, a dew catcher and the perfect CAM perimeter plant.

Yucca filamentosa makes an excellent green roof plant for Florida
Planted in mass, Yucca filamentosa acts as a green roof parapet, allowing interior plants a more welcoming ecosystem for growing.  This green roof plant has not only survived, but thrived on some of our older green roofs!

Yucca filamentosa also has long hairs growing from the leaf edges, allowing for water vaopr in the air to collect as the humid breezes flow across the plant.

Turbulence is another factor necessary to help drop the condensed air water vapor from the catcher to the green roof soil below.

Florida Green Roof  Plants Yucca and Agaves, Note the hairs along the plant edges that facilitate dew sequestration

Success of a nature irrigated green roof depends heavily on sourcing a steady supply of water through rainfall, fog, dew and even frost. Understanding biomimicry based green roof planting layout allows for important air water vapor collection.

Additionally, understanding the principles behind Agave's and Yucca's' water capture successes lie also in an understanding of air humidity.  Humidity is the amount of water vapor in the air. 

Humidity is an important source of irrigation for nature irrigated green roofs and is often present when rain is lacking.  Humidity is often described in terms of ‘relative humidity’ and ‘dew point’.

Relative humidity is the phrase commonly used by weather reporters to communicate the percentage as the amount of actual water vapor in the air divided by the amount of water vapor the air could hold. 

A relative humidity of 75% means air contains 75% of the amount of water vapor possibly held.
Yucca acts as a dew catcher to provide moisture to other Florida green roof plants

Dew point refers to lowest air temperature where water vapor remains in vapor form.  Once the ambient air temperature reaches the dew point temperature the water vapor condenses into dew or liquid.

Dew and fog reference and collection resources available on the web include;
  • Fogquest.org is a great informational resource on capturing dew and fog 

Air humidity can be a significant component in the irrigation of any green roof system.  Consider those months with lower than average precipitation and check to see if dew occurs frequently.  Validate the average relatively humidity percentages.  

Think of the times you have walked across a lawn in the morning to find your shoes soaking wet.

Research dew and fog collection websites.  Look to the green roof plants you work with to see what species appear to accumulate dew. 

Mimic nature.  Mimic the Yuccas and Agavaceae.

Saturday, March 22, 2014

Green Roof Benefits for Florida; Cleaning Air Pollution, Battling Cancer and Other Respiratory Diseases

Green roofs and living walls can help clean the air and allow us to breath easier.  They can also keep us from becoming sick or ill, even contracting cancer.
Florida Green Roof Plants are the Ultimate Fresh Air Source & CPR System
Today, many geographic locations across the globe have air contaminated with Volatile Organice Compounds also known as VOCs.

Florida Green Roof Plants Clean Air & Remove Pollutants
Volatile Organic Compounds (VOCs) are chemicals created by industrial pollution and automobile engines among other processes.  VOCs are the primary cause of Urban Smog. 
 
They are also responsible for the formation of cancers, respiratory problems and other serious health issues.  Just think of the times you have seen city smog envelope an urban area, filling the area with obnoxious and dangerous particulate matter.

According to the US EPA, the Health Effects of VOCs include:

Eye, nose, and throat irritation; headaches, loss of coordination, nausea; damage to liver, kidney, and central nervous system. Some organics can cause cancer in animals; some are suspected or known to cause cancer in humans. Key signs or symptoms associated with exposure to VOCs include conjunctival irritation, nose and throat discomfort, headache, allergic skin reaction, dyspnea, declines in serum cholinesterase levels, nausea, emesis, epistaxis, fatigue, dizziness.

Even our children understand the importance that plants play in cleaning air, see: http://www.clean-air-kids.org.uk/airquality.html .

The ability of organic chemicals to cause health effects varies greatly from those that are highly toxic, to those with no known health effect. As with other pollutants, the extent and nature of the health effect will depend on many factors including level of exposure and length of time exposed. Eye and respiratory tract irritation, headaches, dizziness, visual disorders, and memory impairment are among the immediate symptoms that some people have experienced soon after exposure to some organics. At present, not much is known about what health effects occur from the levels of organics usually found in homes. Many organic compounds are known to cause cancer in animals; some are suspected of causing, or are known to cause, cancer in humans.
Green Roofs in Florida not only provide clean air to humans but to wildlife also
For more health information on VOCs from the EPA click here. 

According to a new study - one confirming what we already know - plants -  - clean these harmful VOCs out of the air.   Read about the study in a National Science Foundation Article here.

This study makes it clear that it is especially important to have as many plants inside your building or home as the levels of VOCs inside a structure can be up to ten times the ambient levels outside.

Green roof plants can save our respiratory systems!

Plants act as filters for air and rainfall, actually removing and utilizing harmful nitrogen.  They also remove carbon from the atmosphere by using CO2 to produce much needed energy compounds and then plants pump oxygen back into the atmosphere.

Some have said that for every twenty thousand leaves in a city (a small tree - for an interesting note on how many leaves are in a tree see: http://www.wired.com/wiredscience/2012/12/how-many-leaves-are-on-this-tree/ )enough oxygen is produced each day for one person to breathe clean air.

As we are bombarded with pollutants each day, in our water and in the air - installing interior living walls, exterior vertical green - green roofs and living walls, Urban Permaculture - City Gardens, wildflowers and trees - can pay off with significant benefits.

Ultimately, we may live longer.  Ultimately, we may beat the odds with cancer or respiratory diseases.
Green Roofs in Florida clean air and can grow food
Restoring Volumetric Green to the Urban Core is critical.  Today, go out and plant a seed or a grown plant.  Bring another inside.  Hang plants from your patio walls and your kitchen window.  Keep plants in your home.  Install a green roof.

Green roofs and living walls - cleaning stormwater, creating habitat, providing a sense of place and beauty and - importantly - fighting disease by removing pollutants!

Surround yourself with plants today.  You may breath better and live longer. 

Remember, the benefits of adding volumetric green to the Urban Core include;

  • Cleaning Rainfall runoff and stormwater
  • Providing wildlife habitat
  • Supporting biodiversity
  • Creating habitat for endangered plants
  • Integrated pest management - supporting pest consuming invertebrates and amphibians
  • Noise insulation
  • Reducing Heat Island effect
  • Creating a Sense of Place and Landscape Beauty
  • and more

Friday, March 21, 2014

Florida Green Roofs, Six Must Have Living Roof Plants

Enjoy the photos of six of my favorite drought, salt, heat, cold and hurricane tolerant green roof plant species!  See more photos of additional plants on the Green Roof Wildflower website.  Wildflowers on #greenroofs are totally awesome.

Florida Green Roof plant, Coral Bean, Erythrina herbacea
Drought, salt and heat tolerant.  Hummingbird plant.
Florida Green Roof plant, Prickly Pear Cactus, Opuntia humifusa
Very drought tolerant, great coastal green roof plant for habitat and pollinators
Florida Green Roof plant, Fleabane, Erigeron app.
Tolerates wet and dry soils, wind and heat tolerant, excellent pollinator plant
Florida Green Roof plant, Blanketflower, Gaillardia puchella
Amazing hardy green roof plant, tolerating salt, wind, heat and other environmental challenges
Florida Green Roof plant, Purple Coneflower, Echinacea purpurea
Hardy, drought tolerant green roof plant that pollinators LOVE!
Florida Green Roof plant, Black Eye Susan, Rudbeckia hirta
Stunning rooftop bloomer that will flower all summer and call pollinators for miles around

Monday, March 17, 2014

Coastal Green Roof Plant, Railroad Vine, Ipomoea pes-caprae Creating a Living Roof

Here is another photo of a living, green roof created by Mother Nature's amazing coastal, salt-tolerant beach plant, Railroad Vine, Ipomoea pes-caprae.
Florida Green Roof Plants - Ipomoea pes-caprae, Railroad Vine
This plant is potentially a great addition to any coastal green roof design.  With its ability to grow into the salt water, withstand extreme heat, drought tolerant and inorganic soil media loving characteristics, Railroad Vine is a potentially great choice for many tropical, coastal green roof projects.

Here, in the above photo, the vine has colonized a parking cone, growing up into the top and outwards, creating a 'mini-green, living roof', providing habitat, attracting pollinators and shading the cone.

Nature can teach us so much about living walls and green roof design.

Coastal green roof plant, Railroad Vine, Ipomoea pes-caprae
Coastal green roof plant, Railroad Vine, Ipomoea pes-caprae

Friday, March 14, 2014

Living Wall by the Consummate Artist, Mother Nature - How I Learn About Green Roofs and Living Walls

The best school to attend to learn about Florida green roofs and Florida living walls is 'Mother Nature's' School of Urban Green.  This holds true of any coastal area, or any other area for that matter.
Florida living wall  - green roof by Mother Nature, Resurrection fern, Pleopeltis polypodioides growing out of a concrete bridge platform
As a novice designer of vertical green compared to Mother Nature, I am always looking to her to learn about growing plants on a rooftop or up a wall.
Florida green roof - living wall by Mother Nature, Resurrection fern, Pleopeltis polypodioides growing out of a concrete bridge platform
Yesterday I was on my bike, doing my daily physical therapy to hopefully maintain my dissected aorta in some sense of health, when a lush, vibrant and very tropical looking group of plants caught my eye.
Florida living wall example by Mother Nature, Resurrection fern, Pleopeltis polypodioides growing out of a concrete bridge platform
Resurrection fern, Pleopeltis polypodioides, had covered the vertical side of a concrete slab bridge platform above a creek.

Florida living wall  - green roof by Mother Nature, Resurrection fern, Pleopeltis polypodioides growing out of a concrete bridge platform
Nature had created a beautiful living wall, vertical green with resurrection fern, Pleopeltis polypodioides, and without any soil, fertilizer or artificial irrigation sources.

How does she do it?  The best way is to examine the surrounding ecology as an integrated unit.

The concrete slab provides a growing platform similar to rock and gathers solar heat during daylight hours, providing a warm area for the plant to attach roots.

The creek below contributes humidity to the air.  A bioswale could mimic this water source below a concrete wall in the urban core.

Adjacent trees provide shade and tell the green roof or living wall designer that resurrection fern may probably grow well in the shade.

And so much more information right in front of my face.  Ten minutes studying the natural living wall creation told me more than hours worth of reading would have.

Mother nature is such an amazing artist and teacher!



Sunday, March 9, 2014

Florida Green Roof Images, Herbs and Roses on the Roof

Herbs on the Florida Green Roof.  Parsley, sage rosemary and thyme.  Yesterday Breaking Ground Contracting #GreenRoof photos.
Green Roofs in Florida, rosemary and garlic chives, herbs on the roof

Green Roofs in Florida, Louis Philippe antique rose and Florida native yucca filamentosa

Green Roofs in Florida, aloe and yarrow growing on the living roof

Green Roofs in Florida, aloe is such a great rooftop medicinal plant, drought tolerant & hardy

Green Roofs in Florida, aloe in bloom on the rooftop


Green Roofs in Florida, Louis Philippe rose buds, such a lovely rooftop plant

Friday, March 7, 2014

Coastal Green Roof Plants and Cross Section Design for Florida and the Tropics


Designing any green roof involves integration of many site physical, meteorological and biological variables, the actual creation of an ecosystem so to speak.  Coastal green roofs, those with salt impacts, are especially complicated.
Green roofs for coastal structures can present complicated issues to overcome +MetroVerde
Among the biggest variables to be considered during design are wind, salt and fire.  Salt spray will kill most landscape plants.  Around the clock steady to cyclone-strength winds can strip soil media right off and out of a green roof, rendering the system uninhabitable and possibly sandblasting an adjacent structure.  Accumulated biomass can fuel a lighting started wildfire across adjacent lots, wind carried sparks igniting a dry living roof and burning through a roof deck.

So we look for those plants that will grow despite salt, continual desiccation, fire potential and the geological components that successfully support them when designing a coastal green roof.
Coastal Green Roof succulent, seashore elder, Iva imbricata +MetroVerde 
Not only do I enjoy walking along the dunes because of the sense of beauty, the salty smell, the warm sun and sense of relaxation, but the seashore is rich in examples of vertical green, nature created green roofs and native living walls.
Coastal Green Roof plant, seashore elder, Iva imbricata +MetroVerde #greenroofs
Surprisingly, here in Florida there are some really good plants for a coastal green roof.  A walk along the dunes relaxes and teaches.  I recommend a good handbook, one such as The Smithsonian Guide to Seaside Plants of the Gulf and Atlantic Coasts or Florida's Living Beaches.
Native salt tolerant living walls by mother nature +MetroVerde , Florida living walls, Dune Daisy
Mother nature also does an awesome job creating spectacular salt and drought tolerant living walls along the shoreline.  Better than any design guide, beach strolls with camera, pencil and paper will show the designer what works and what does not.
Native salt tolerant living walls by mother nature +MetroVerde , Florida living walls, purslane
The following is a partial list I usually see growing well along the frontal portion of the dunes, in the harshest and most exposed areas.  I would use most any of these on a coastal green roof in the tropics or along the Gulf and Atlantic shoreline.
But there are many more waiting for the designer to discover themselves!

Of course wind is a big challenge.  Wind can kill those plants not possessing protected photosynthesis pathways.  It is always good to review the differences in C3, C4 and CAM pathways when designing any green roof, but absolutely crucial for a coastal green roof.

Coastal Green Roof Cross Section - Typical Design +MetroVerde copyright MetroVerde 2014

Above is a general sketch of a design approach we may take in creating a coastal free roof subject to cyclone winds.  Of course the roofing assembly will need to be fire rated Class One.  Your roofing contractor working with the roofing supplier can specify the appropriate fire rated materials.

If you use all succulents on the coastal green roof you may not need to design in buffers, yet even the juiciest succulents can burn under the right conditions.

Be sure to follow ANSI, IBC and local standards and codes when designing a coastal green roof.

Seaside green roofs can be very complicated to design, but the very best teacher is always available.  Just hop in your car and drive down to the beach.  Mother nature's creations are phenomenal!