Green Contractor's Office Provides Habitat with Native Plants and a Green Roof

Jacksonville's Breaking Ground Contracting (BGC) office sports a green roof and landscape comprised of native plants and grasses.

Breaking Ground Contracting's front landscape utilizes Yucca filamentosa and the Hyla cinerrea (green tree frog) loves the habitat (photo by M. Tappouni)

The front bed is filled with Yucca filamentosa, one of Florida's native yuccas and a great habitat provider for wildlife.

Importantly, the BGC office incorporates volumetric green from the street to the roof.  Native grasses extend from the edge of the roadside right-of-way to the front door, around the building and up to the rooftop.

Interconnected corridors of green create animal habitat, providing foraging and communal opportunities for wildlife in the Urban Core.

These photos were taken my Mary Tappouni who owns Breaking Ground Contracting (I borrowed them from Twitter for this post).  The Florida green tree frog is a Hyla cinerea.  H. cinerea is under predator pressure from the larger, more agressive and invasive Cuban Tree Frog.  However the native plants across BGC's site provide refuge for the smaller native tree frog.

Soon after the BGC green roof was installed, H. cinerea appeared  on the rooftop vegetation.  I suspect several eggs came in on native plants.

Though small and almost unnoticeable, H. cinerea is a voracious eater and can consume a great amount of  otherwise pest bugs such as mosquitos and roaches.

Breaking Ground Contracting's front landscape utilizes Yucca filamentosa and the Hyla cinerrea (green tree frog) loves the habitat (photo by M. Tappouni)

Creating habitat for native wildlife is an important facet of Urban Greening.  Year after year, the Breaking Ground Contracting office's landscape is successfully providing foraging and communal refuge for Florida's native wildlife.

You can find out more of the BGC green roof and sustainability efforts here.  The Breaking Ground Contracting website is http://breakinggroundcontracting.com/

City Greening - A Wonderful Publix Landscape Screen

Most stores on main roadways want maximum exposure.  Driving up and down our city streets we are typically greeted with glaring neon lights, tall concrete structures, multi-colored signs and more of the industrial urban commercialism.

Seldom is the occasion when a major grocery store chain designs a thick screen of native plants between the store and a highway such as A1A her on the east coast of Florida.

A1A Highway & Native & Florida Friendly Landscape Screen, Publix Grocery, Hammock, Florida

A1A is one of the longest, scenic and most historic of highways in Florida and is frequently travelled by many motorists.

Live Oaks, Palms & Cedars, Landscape Screen, Publix Grocery, Hammock, Florida

So it stands to reason Publix would have wanted maximum exposure to automobiles driving past their store in Hammock, Florida.

Instead, even though the store is only a few feet from the edge of A1A's right-of-way, the designers installed a very dense hedge of native shrubs and trees, along with Florida Friendly landscape plants.

Live Oaks, Palms & Cedars, Landscape Screen, Publix Grocery, Hammock, Florida

And you can hardly see the building from the road.

Even though there is a large grocery store and big asphalt parking lot behind the native landscape, the man-made structures are practically invisible to those riding by.

Instead, one is greeted with the beauty of Florida live oaks, palms and cedars.

Unexpectedly, the native plant screen may actually attract more customers by hiding the store.  When I drive by I am aware there is a store there even though I cannot see most of the building.  My curiosity is aroused and I slow to look through native plants at the business.

Maybe Urban Greening actually attracts more customers.

Even so, the native plant hedge provides many benefits to the store and community.  The plants provide habitat for wildlife, sequester carbon, pump oxygen into the air, provide cooling shade, offer beauty and more.

My architect friend, Rob Overly says something to the extent that Urban Greening must start at the doorstep, connecting the roadways with the structures.

Live Oaks, Palms & Cedars, Landscape Screen, Publix Grocery, Hammock, Florida

 Publix has done just that, an excellent job with Urban Greening in the Hammock, Florida location.  To view the landscape and the store take A1A south from Marineland.  The grocery store is a couple miles south of Bings Landing on the east side of A1A.  You'll have to be looking for live oaks, palms and cedars to find the grocery store.

Green Roof and Urban Greening Plant, Monarda punctata, Spotted Bee Balm

Undoubtably, Spotted Bee Balm, Monarda punctata should 'bee' a required plant for most if not all North American green roofs, living walls, xeriscapes and urban greening projects.

Green Roof & Urban Greening  Plant, Spotted Bee Balm, Monarda punctata a native wildflower

This week's photos shown here are of the Lamiaceae's (mint family) hardy native growing only a couple hundred yards off Florida's Atlantic ocean shoreline.

Spotted Bee Balm is a pungent native wildflower with a natural range across most of the United States and much of eastern Canada, with a sub-species, M. punctata spp. immaculata endemic to parts of Texas.

Spotted Bee Balm is listed as a historical plant in Kentucky, and protected as endangered in Ohio and Pennsylvania.

Green Roof & Urban Greening  Plant, Spotted Bee Balm, Monarda punctata growing in sand dunes

Importantly, Spotted Bee Balm grows very without additional irrigation in the harshest of places, making her a wonderful landscape plant for xeriscape projects.

As a native wildflower, her nectar attracts many Lepidoptera and other pollinators.

Green Roof & Urban Greening  Plant, Spotted Bee Balm, Monarda punctata, Florida wildflower

Here in Florida, Spotted Bee Balm grows vigorously on the hot, dry beach dunes, across desert-like roadsides and just about anywhere you can find a sandhill or flatwoods.

Green Roof & Urban Greening  Plant, Spotted Bee Balm, Monarda punctata an important permaculture plant

Popular for use in teas, Spotted Bee Balm is high in thymol content and other phytochemicals.

Though often confused in use with Citrus bergamia, the bergamont orange and recognizable component of Earl Grey tea, Spotted Bee Balm tea is reported to possess a calmative effect due to the thymol derivatives found in leaves, terminal buds and flowers.

Green Roof & Urban Greening  Plant, Spotted Bee Balm, Monarda punctata 

For Urban Core greening and green roofs, Spotted Bee Balm is a natural choice.  As a native wildflower, the plant is already adapted to many climates across North America.  Numerous pollinators utilize M. punctata.  Ethnobotanically speaking, the plant has many culinary and medicinal uses.

Spotted Bee Balm can be used as an annual or perennial, depending on the climate's average winter temperatures, but can be counted on to reseed or come back from roots on a reliable basis.

Ideally suited for green roofs, Spotted Bee Balm will provide excellent late summer color and vegetation, long after the Gaillardia and Helianthus have dried and gone to seed.

Green Roof & Urban Greening  Plant, Spotted Bee Balm, Monarda punctata a native wildflower

Seeds are available through numerous internet resources, including Prairie Nursery and Sand Mountain Herbs.

Florida Permaculture Garden's Hot & Spicy Basil Habanero & Banana Pepper Jelly

Florida Permaculture Garden is full of ripe habanero peppers.

Florida Permaculture Garden's habanero, chili, jalapeño & banana pepper's & spicy globe basil

Wondering what to do with the hot, hot, hot produce we took Rob Overly's Facebook suggestion and made hot and banana pepper jelly with the bountiful harvest.

Spicy globe basil leaves were added for a touch of summer taste.

The jelly batch turned out to be one of the tastiest, most delicious permaculture garden foods we've yet ended up with.

The hot and spicy globe basil - banana pepper jelly will go well with fish, turkey and any meat dish, be tasty on a bagel or with whole wheat crackers and cream cheese and as a salad accompaniment. 

Spicy globe basil adds summer taste to permaculture jelly!

And I thought the way too hot peppers would make the jelly inedible.  Instead, the spice level was just right, even for Judy who is ultra sensitive to hot foods.

Last night's first batch of the summer will definitely not be the last.

Here is the permaculture hot banana pepper & habanero jelly recipe:

Pick a colander full of bot hot and banana peppers - be sure to use gloves as these may be HOT!

Florida Permaculture Jelly:  Step One: Slice Open Hot Peppers

Deseed.

Florida Permaculture Jelly:  Step Two: Deseed hot peppers

Rinse three times in colander.

Florida Permaculture Jelly:  Step Three: Rinse hot peppers

Chop in food processor into small chunks.  Do not over process.  The pepper chunks should be about the size of a large grain of rice.

Florida Permaculture Jelly:  Step Four: Boil vinegar, peppers and sugar

Rinse chopped peppers again.

Place chopped peppers into a large sauce pan.  Add 1 cup of apple cider vinegar for every 3 half pint jars of the jelly you wish to make.

Bring slowly to a boil.

Just before the pepper and vinegar mixture reach boil, add 3 cups sugar for each 3 half pint jars of the jelly you wish to make.

Gently boil for three minutes, stirring constantly.

Turn heat off and immediately add one pouch pectin or Sure-Jell for each 3 half pint jars of the jelly you are making.

Stir until the pectin is dissolved.

Add several small basil leaves to each half pint jelly jar.

Spoon several large spoonfuls of the chopped peppers into each half pint jelly jar.

Florida Permaculture Jelly:  Step Five: Pour into Jelly Jars

Ladle the hot jelly liquid into cleaned and warm jelly jars.  Cap and let cool and seal.

Enjoy some of the best hot pepper and basil jelly you've ever put into your mouth!

Florida Permaculture Jelly:  Step Five: Pour into Jelly Jars

Note:  The combination of cider vinegar and hot peppers may cause a burning sensation in your eyes!  be sure to open your windows, provide adequate ventilation or wear a dust mask while cooking!

Rabbit on a Stick, Green Roofs, Fresh Fertilizer & Florida Permaculture

My green roof friend in France, Pascale says to eat rabbit on a stick with mustard.  It sounds good, but I've never tried rabbit on a stick.

Florida Permaculture Garden's Jack Rabbit in his Green Roofed Pen

However in the Florida Permaculture Garden rabbits played an important permaculture role.  The bunnies provided us with some of the most potent, ready to use fertilizers.

Ruby the Rabbit, Florida Permaculture Garden

In the Permaculture Garden, rabbits are one of the easiest livestock animals to keep.  They are quiet (except when a predator is around), their poo is ready to use without the required cooling off period normally associated with chicken manure, they are tasty and reproduce at lightening speeds.

Permaculture Green Roof for Rabbit Pen under construction

Our rabbit hutch has a vegetated roof.  Simple permaculture concepts.  Rabbits eat clipped forage off their green roof, rabbits grow, rabbits poo, we use the rabbit poo to fertilize and grow more plants on the rabbit hutch green roof, rabbits produce more rabbits and green roof plants feed the babies.

Rabbit forage on the Pen's Green Roof

Perfect perpetual motion machine.  Almost.

Fortunately, the rabbit hutch green roof was not expensive.  In fact, the hutch was built with only recycled stormwater panels, used felt material, wood scraps, old tin sheets and some chicken wire left over from the hen coop.

Remember, for green roofs on the cheap - structure, soil media and proper plants!

The rabbits loved their 'green' coop and the living roof kept them cool during the hot summer months.

We had the very best permaculture fertilizer one could have, a gift from the rabbits in return for their 'green' digs.

Florida Permaculture Garden's Green Roof Rabbit Pen makes for happy & hoppy bunnies

Much the way many living wall designers use felt or a non-woven geosynthetic, I rolled and inserted the felt fabric into the stormwater panels for a base growing platform.  The panels were placed atop a standard piece of roofing tin over wooden rafters above the rabbit cages.

Simple piece of tin covers the pen rafters under the DIY green roof system

The purpose for using the 50mm stormwater panels was to give the living roof a structural dimension, one that would place the weight of the green roof over the stronger outside pen supporting walls rather than on the rafters.

A reused gutter drain served as a green roof crown cap

Once the felt was embedded, rabbit poo, leaves and compost was added to the panels.  Garlic, rye and  other forage plant seed was added.  Soon the roof was green with tempting bunny forage.  The felt acted to wick water across the roof,  provided oxygen, drainage and a structural grid for roots to attach to.

Green roofs don't have to be expensive.  Think - support, innovative soil platform and proper plants.

As for the rabbits, try on a stick with mustard!

Native Plants for Urban Green, Permaculture & Green Roofs

The bioswale is looking great!

LaSalle Bioswale Project - Native Plants for the Urban Core

We were out on errands day before yesterday and Judy had library books due, so the San Marco library was a stop on the list, and I was thrilled.  You see, Riverkeeper and Coca Cola funded a stormwater project I've mentioned before called a bioswale in front of the city facility.

Of course there were engineers involved (Doug Skiles) and plant people like Bob Chabot and Chris Dailey from the Jacksonville Zoo and Gardens, and others.

The Bioswale takes the place of the old right-of-way landscape

Though a stormwater ditch may not sound much like an Urban Green project, nor may it be as glamorous as a green roof or front yard filled with food plants, it is important to all the above.

I have to keep reminding the botanist in me about the importance of native plants.

San Marco's library bioswale is filled with ethnobotanically important native plants.

Cordgrass, Muhly grass, Cypress, Ilex and curbcuts gather and treat stormwater

However, many times these native plants are looked down on by, yes, even those involved in Urban Green, Green Roofs and Permaculture efforts.

Maybe due to their 'commonness', or lack of pretty, patented fluorescent flowers (though many native species are stunning in their own right), or minimal fruiting-food production, natives are out-of-vogue with a large component of the Urban Green movement.  In fact, in the Urban Farm movement, little if any thought is given to the impact of planting food plants that may themselves be another eventually invasive or monoculture problem.

Native plants provide habitat for native pollinators

Sometimes this may be due to the fact that urban farmers, green roof designers and permaculturists are used to thinking along the lines of only one mindset (including myself).

Yet the plants here are just as rich in ethnobotanical value as any exotic plant such as moringa, without the dangers of becoming invasive.  Though preached and loved as the ultimate plant, moringa has been classified as a potential dangerous plant for native habitats (see Michigan Technological University's website).

Existing utilities were worked around during design and installation

Other times it may be because of a lack of education and information about the true value of native plants to Urban Green, Green Roofs and City Permaculture projects.

But the San Marco bioswale brings all that back to mind very quickly.

The native plants growing in the San Marco bioswale not only clean standing and flowing stormwater, they are able to withstand long periods of drought without additional irrigation.  This is important because of our present water supply crises.  The plants can adapt to either floods or dry periods, without having to turn on the hose.

Native plants provide the transition beauty from street to building

Urban landscape, green roof and farming irrigation add up to be a significant amount of water use in our cities.  Hopefully, projects like the San Marco bioswale can educate us all to the fact that native plants can provide landscape beauty without added irrigation.

Yet there is more.  As I was walking around the bioswale, I noticed hundreds, if not thousands of dragonflies, damselflies and other insects.

Because of low leaf litter rate and ability to survive drought or flood, Cypress is perfect for bioswales

The bioswale was acting as a virtual breeding nursery for pollinators, those same pollinators permaculturists pray for around their gardens.  The native plants provide habitat for native pollinators to breed, forage and live in.  Without native pollinators there can be no food gardens.  Without native pollinators there will be no flower pollination.  Without native pollinators there are no city farms.

Importantly, we must recognize mistakes we as a culture have made in the past bringing in exotic plants for food, erosion control and landscape beauty that eventually have turned into nightmare plants.  Kudzu, wisteria, Mexican petunia and potato vine are just a few of many.  Unleashing plant monocultures that choke out native grasses and other plants has been a process that once we start has been difficult to rehabilitate.

The disappearance of many native pollinators and beneficial insects, amphibians and reptiles can be directly related to the use of food and landscape plants from foreign ecosystems that having once arrived, take over and preclude habitat for the native species.

Once our native species are gone we are left with a hodgepodge of alien plants.

Unfortunately, though gaining in popularity, native plant landscape are still under-appreciated for their biodiversity, pollinator support and habitat providing value.

Permaculture, green roofs and Urban Green have come a long way.  They still have a long way to go with respect to incorporating native plants.

Hopefully, projects like the San Marco bioswale will teach us about why we need a majority of native plant species on our green roofs, permaculture gardens and Urban Core Green.

Best Pickled Okra Recipe - Florida Permaculture Garden

Some food traditions are hard to beat.  One of those here in the South is pickled okra.

Grandma's Pickled Okra Recipe

I love pickled okra.  My wife, Judy loves pickled okra.  My teens, Jincy and Ruairi especially love pickled okra.

Something about the texture and taste that turns a full jar into an empty jar within a matter of seconds.

Buying pickled okra here is expensive.  Most supermarkets carry the treat but charge three, four or five dollars per jar.

Fortunately however, okra is easy to grow and just as easy to pickle!

Okra originated in Africa, probably somewhere near present day Nigeria. Referred to as Abelmoschus esculentus by botanists, okra came to the new world on Middle Passage voyage ships.  Known by other names, such as gumbo and quimbombo, okra is found today growing across the world.

Burgundy Okra, Florida Permaculture Garden

In fact, we have more okra growing in the Florida permaculture garden than any other food plant and the plants produce significant quantities of pods.

So when the other day Mom sent me my Grandma's Miami, Florida pickled okra recipe I just had to make a batch.  Picking a bowl of okra and banana peppers out of the garden, I peeled a couple cloves of garlic, added dill seed and salt and heated white vinegar.  Soon we were feasting on the most delicious pickled okra I've ever eaten.

It was great to see my Grandma's handwriting once again too!

Grandma Belle's Pickled Okra Recipe 

HVAC Air Intake Covered in Plants - Green Roofs and Living Walls Filtering Air Flow

Newton, the Ask a Scientist, Scientist - available for consultation from the U.S. Government - click here for Newton's Website... - 

...says 53 Liters is the amount of pure Oxygen the average adult needs to survive every hour.  53 liters is approximately 14 gallons.

You can see we use alot of oxygen on a regular basis.  Now picture your bedroom and night or your office during the day.  For estimation purposes we will use an office space of about 5,000 SF with a 9' ceiling and containing 24 employees.  The Office contains  336,600 gallons of atmosphere.

Green Roof Plants filter toxins and produce oxygen

According to Newton the air we breathe contains about 21% oxygen so the office will contain 70,686 gallons of oxygen.  Is this enough to last the 24 employees for a day?  Let's find out.

Each employee breathes 14 gallons of pure oxygen per hour - more if they are active but most office workers are sedentary - so each employee breathes in120 gallons per shift and the office as a whole breathes in 2,880 gallons of oxygen per shift. 

OK - that's plenty of oxygen to start, but within a month without the doors and windows being opened the employees will rapidly use up all the oxygen.  How old is your office?  How old is your house?  When is the last time you've flushed the air in your office or house?

Just think, without the windows being open, you are breathing stale air - air already breathed in many times over by others in your office or house.  This air contains not only stale exhale of others (and suspended germs) but volatile toxins off-gassing from carpet, furniture, paint and other manufactured goods in the office or house.

And the unfortunate part of the whole equation is - we keep our windows shut most of the time.

However, there is a solution - plants!  Plants produce oxygen as a by-product of photosynthesis.  Your personal oxygen machine is as readily available to you as setting a plant on your desk.

I suspect all employees would be happier if air intakes for HVAC systems (most residential systems are closed loop systems) were covered with vines and pumped full of oxygen.

Moreover, plants are extremely efficient at removing toxins from the off-gassing process.

Green roofs and living walls are a key component to filling our sometimes stale Urban Core with fresh oxygen.  Imagine buildings downtown covered in plants and those plants pumping out oxygen daily.
The roof-based vegetated air intake tunnel keeps a building roof vegetated and provides additional benefits, including;

1.  Cools intake air
2.  Shades the roof
3.  Removes airborne toxins, and more!

MetroVerde Intake Tunnel Alternative to Green Roof

 

Additional benefits allow for reducing heat island effect, providing shade, cleaning stormwater, wildlife habitat and much more.

Restoring volumetric green to the Urban Core.

Green Roofs are the key to healthy cities.

Green Roof Plants; Insulation & Thermogenesis Issues

All plants possess biological systems that directly impact our ecology and the immediate environment surrounding our day to day activities.

After purchasing a truck load of plants on Saturday we unloaded most, however forgot to remove all of the plants from the cab.

Though the night air was cold (6C) when I opened the truck door and climbed in to drive to the market yesterday evening, after dark, I was enveloped with warm, moist air and confused as to why - with the cold dry air outside - the truck windows were fogged over with moisture.  Then I realized the plants were still in the truck, taking in CO2 and pumping moist O2 back into the air.

After spending much of Saturday evening outside taking temperatures with the ExTech IR thermometer, the oxygen and moisture filled truck cab emphasized what I already knew - plant's biological process are complex and have definite effects on their surroundings.

Sometimes we forget just how much plants impact our environment.

However in addition to the wonderful visual greenery (again we sometimes take for granted), plants sequester CO2, produce O2, provide habitat for wildlife in the Urban Core, provide food, fiber and medicine, clean stormwater and provide a myriad of other functions.

All of these factors and processes impact green roofs.  Understanding how these factors interact with the building is important.

This weekend I wanted to gather additional data on heat and green roofs.  My questions were many and included;

* Do green roofs really act as insulation?
* Do green roofs act as a heat sink - storing heat - instead of being an insulator?
* Does green roof plant selection impact the energy efficiency of green roofs?
* Does green roof soil composition impact energy efficiencies of green roofs - and if so, how?
* and a host of other questions.

After spending several hours with the IR, examining plants and green roof systems after dark - and in 6C ambient air, I can say much data needs to be collected, many studies completed and analysis done before we really understand the dynamics of green roofs.

Just as with the fertilizer and irrigation issues (I am always amazed at how some promote green roofs as ecologically friendly and important yet insist for the inclusion of potable water irrigation systems and fertilizer applications), the insulation or heat sink issues just don't seem to be adequately answered.

After collecting temperature data from under green roofs we see a green roof behavioral trend pointing to a heat sink rather than an insulator type system.  In other words, green roofs may tend to absorb heat during the day and then slowly release it back into the atmosphere and building during cooler evening hours.

Yet the complexities of plant species, plant growth characteristics, root systems, stomata to leaf surface area ratios, soil media specific heat qualities and other issues all contribute towards a complex model.

Getting back to the IR thermometer field  foray, some of the more interesting observations we noted were;

* Night time green roof plant leaf temperatures were approximately the same as ambient air temperatures,
* There were variable levels of warmer temperature readings found in the air space under the green roof plant leaves and above the green roof soil media, depending on the time of night and wind exposure - suggesting a level of insulation occurring as a result of leave structure
* The underside of an extensive green roof (3" soil media) stayed 10F warmer than a similar roof with no green roof system - and stayed warmer all night -- up until 5am the next morning,
* Banana plants stayed considerably warmer than ambient air for up to three hours after dark - unlike other plants,
* and other observations.

The banana plant elevated temperatures pointed us in the direction of thermogenesis in plants.  Thermogenic plants are those plants that can generate heat as a result of biological processes. The voodoo lily, Sauromatum guttatum, can generate temperatures of up to 110F - 32C!

There is a great video on thermogenic plants here.

However, the banana plant is not a thermogenic plant and the reason the banana plant stayed warmer than ambient air for several hours after sunset was the plant's high water content.  Water has one of the highest specific heat values of any compound or substance - four times than of limestone for instance.  Because the banana tree was full of water, the solar heat gain experienced during the day only slowly dissipated after nightfall.  Banana trees stayed warmer than most plants after dark because of the heat stored in the large volume if interstitial water within the plant.

It is possible the succulent filled extensive green roofs we are studying that emanate heat throughout the night are behaving like the banana plants.  The combination of green roof soil media and the water therein is absorbing heat during the day - maybe quite a bit of heat - then slowly releasing the heat at night.

The factors involved in modeling this complex heating and cooling dynamic are many and not well documented today.

We think the heating behavior of the extensive green roof is due to water in the extensive green roof plant root systems.  Because the system studied was non-irrigated (nature only irrigation), the soil media was rather dry.  However for heat to continue to be released for long hours, the heat source probably was water - and probably water stored in the underground parts of plants.

We ask ourselves many questions - if water is a significant heat sink and heat source, then do green roofs really act as insulating systems?

If green roofs are heat sinks then how much heat do they dissipate back into a building at night?

Are irrigated green roof systems actually hotter than non-irrigated vegetated roofs or reflective white roofs?  If so by how much?  How much cooling does plant transpiration and evapo-transpiration on irrigated green roofs?

There are many questions to be answered.

As an industry we need to sponsor and encourage more study of green roof thermodynamics.

Green Roofs and Hurricanes, Wind Events and Tropical Storms

Hurricane and cyclone season is here.  The month of May marks the time each year when the National Hurricane Center says potential for tropical storms begin.  We are in the middle of July and have already had numerous tropical storms hit here in Florida.  Though wind damage was not as bad as it could have been, flooding was severe in certain areas.


But we are moving into the heart of summer and with warmer waters, one should expect an increase in tropical storms and cyclones soon.

Residents of areas prone to cyclones are familiar with the damage high velocity winds can do to buildings and especially roofs.  It is important that any green roof design installed on structures in Florida or other tropical climates subject to storms be fully tested with hurricane simulators for resistance to blow off and destruction.

Hurricane testing of green roofs is important for several reasons.

University of Florida Hurricane Simulator

First is the health, safety and welfare of people.  Placing any object on a roof not permanently attached is a violation of many building codes and can cause serious damage when blown off in high winds.

Parapets and other wind breaks around flat roofs may help up to certain speeds but trays, mats, pots or containers must be permanently attached.  This means each pot and each tray.  Otherwise liability in negligence may exist (consult your construction tort attorney) if the system blows off and causes damage.

Hurricane simulation testing is not the same as wind tunnel testing.  Be sure your green roof system has been tested out-doors on an engineer designed roof testing system with a wind turbine process.  Wind tunnel testing may not offer sufficient design support to protect against negligence (again consult your attorney).

Secondly, a good designer wants to know if the plants they are specifying will hold up in hurricane conditions.

Many plants may loose upper leaves but their root systems stay in place and they regrow quickly.  There are many good reference articles available on the when concerning right plant selection for hurricane prone areas.

I like built in place systems for hurricane prone areas.  Unless modular systems are permanently attached - I suggest permanently attaching each tray with adhesive - and a blow off occurs with resulting damage - then the issue of tort liability potentially arises (consult your attorney).  In our litigation prone society it is prudent to always hurricane test green roof systems before specifying and installing in those areas possibly subject to tropical storms.

Cyclone winds flowing across a flat roof create uplift like a vacuum and can pull shingles or other roofing material up into the air.  Roof accessories such as pipes, vents, skylights, green roofs, planters and HVAC units are also subject to the wind stresses and may become problematic.

Green roof hurricane preparedness involves several fairly simple and straightforward steps, including;

• Make sure there are no loose objects on the green roof, such as pruning shears, hand trowels or other hand tools
• Check to see if there are any dead plants or large pieces of fallen plant material and remove
• Inspect the green roof system for integrity
• If the green roof system is a tray system, make sure the trays and not damaged by UV degradation and ensure no loose edges are exposed
• If the tray system is a mat system, check for loose mat edges
• Review the underside decking in the attic for any water stains or other indicators or leaks
• Check to make sure the underlying structure is holding its form and nto sagging fromt he weight of the green roof
• Replace organic material and soil amendments as needed
• Look for adjacent dead tree branches or limbs that could fall on the green roof and have removed
• Make sure there are no mechanical system repair parts left on the roof from maintenance - you'd be surprised at what gets left on a roof - look for loose screws especially!

Well established green roof plants create turbulence across a roof surface, and may act to reduce uplift in some instances.

We'll be posting several articles over the next few weeks dealing with the  topic of winds and green roof plants, with a focus on cyclones, hurricanes and tropical storms.