Monday, August 15, 2011

Green Roof Designs are different than ground level landscapes. Green Roofer Responsibility.

A perpetual optimist, I always hope for the best from people, groups of people and collectively as companies and industries.  I hope most want to do the right thing when green roofing is in focus.

Rooftops are different than ground level landscapes, but check out the sprinklers going!

Maintaining positive industry reputation is critical to the developing green roof industry here in Florida.  Several bad jobs can label the product as 'defective' and quickly turn a positive business atmosphere and outlook into a negative one.

Those doing green roofs in Florida needs to ask for help from someone who understands the different issues facing rooftop plants here.  Florida roofs are different than the rest of the world.   Importantly, although many landscape companies exist across Florida, a ground level landscape is vastly different from a roof.  Consulting a landscape architect or green roof designer who understands green roof design and plants is crucial for the success of a Florida green roof.

Right now there is a relative large project here in Florida where a nationwide company installed a green roof in October of 2010.  The contractor used sedum, which should have never been recommended or used here in Florida and the plants promptly died.

In an attempt to remedy the job the contractor used a landscape company to install perennial peanut sod as a cost effective alternative.

In my opinion, this was an inexpensive remedy with a plant that is known to die back here with freezing temperatures.  Though green roof plants may be expected to die back up north with cold weather, here in Florida vegetated roofs should be green year around.

It appears that a large amount of fertilizer has now been added to the roof to encourage the plants to take hold and the gutter overflow is filled with algae, speaking of high phosphorous or nitrogen applications.

Right now the roof has five garden hoses slung up to the top from down below and for four hours each day or so, five whirly bird sprinklers are spinning around full blast watering the peanut sod in an attempt to moderate the 120+ F rooftop temperatures and two meter per second desiccating wind (the roof has no protective parapet).

Where the water hits the plants look green.  The other thirty percent of the roof is dead brown. The entire planting is hit or miss.

The sod that is green will continue to look good as long as irrigation water is applied, except where the soil media is being eroded away.

But this is not sustainable and this is not what the green roof industry needs in Florida.  We have a water crises here in Florida and applying large amounts of overhead irrigation to a green roof should not acceptable from an industry perspective.  Moreover, it is not good for the plants as it encourages fungal issues here in our long, hot and wet summers.

A rooftop is not a ground level landscape and must be designed with different restricting issues in mind.

I was always taught to be sure customers received the very best product once you agreed on a design, regardless.

Landscape companies and large roofing companies may have the capabilities to install plants on the roof, but if they do so they seek out qualified design help before experimenting real time.

The green roof industry as a whole deserves and should demand quality work from those participating in the genre.

1 comment:

Rolf said...

I believe that installing a green roof instead of a conventional one is a great idea. However, doing so requires more accurate detailing than ground-level landscapes since green roofs are mainly comprised of layers of vegetation, drainage and irrigation systems. I think it would be best if the crafting and maintenance of these roofs will be left to experts. Green roofing can be labeled as a breakthrough in the roofing industry and it needs to be developed even further.

Avery Simek