Friday, August 10, 2012

Green Roofs & Hurricane Winds - Reviewing UF Wind Tests

With two tropical depressions in the Atlantic and several cyclonical systems developing this August 2012 hurricane season, the October 2010 video of green roof hurricane tests in UF's Civil Engineering facility is reposted along with the original narrative.

As food becomes scarcer and more Urban Ag activities spring up across our cities, material science will play an important role in designing secure plant growing systems for patios, walls and roofs.

Though the video is quite long, Urban Green roof and hurricane design issues require comprehensive attention to potential safety issues, just as any other roofing material or system would demand.

October 2010:

We started off today referring to the Green Roof Wind Uplift Test duration as "until failure".

At least it looked as though the test would proceed until the mat failed.

After all, the MetroVerde Green Roof had been sitting in the hot Florida sun, non-irrigated, 1" thick layer of engineered soil for 18 months at the University of Florida.

We are going into our fifth week of zero precipitation (no rain).

The plants looked brown.

The panel was fixed at a 3/12 slope just feet away from the large hurricane simulator.

The plants appeared vulnerable, the engineered soil just waiting to be blown off the mat along with vegetation.

The large diesel engines fired up and the turbines spun.

50 MPH for one minute -  dust blew off the roof.

70 MPH for a minute plus - not much happened except the plants whipped back and forth.

90 MPH and the dust around the base of the testing platform flew and the plants bent backwards - almost parallel to the roof slope.  Shingles on a shed 300' away began flapping.

We were all amazed, having seen other green roofs under hurricane tests blow away, soil and plants...

We took a break and looked at the panel.  A small amount of the engineered soil had blown off the mat.

The 120 MPH for over three minutes.

The dead, brown material blew off the plants - like a good pruning.  Even the large, tender Echeveria was still there, albeit leaning a little.

The nodding garlic - Allium canadense was beautiful.

The plant roots were so intertwined in the mat that 80% of the engineered soil remained.

Successful.  The first Florida Designed Green Roof Panel to pass the 120 MPH wind uplift test.

Lots learned -

Will be working with UF more in the future!

Enjoy the video - I'll post the link as soon as YouTube finishes processing it - in the meantime here are a couple pics and happy Green Roofing!

MetroVerde Green Roof Passes 120 MPH Hurricane Testing

120 MPH Winds on Green Roof - Hurricane Testing

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