Showing posts with label green roof wind uplift. Show all posts
Showing posts with label green roof wind uplift. Show all posts

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

Saturday, October 30, 2010

Photos of What Hurricane Force Winds (120 MPH) Do To a Green Roof Plant

The photos included here are from wind uplift testing yesterday at UF. Notice the moderate damage to the plant leaf epidermis and underlying palisade layer (dessication).

Observations and photos of recovery will be posted over the next couple months to see how quickly the plants heal from the damage and regrow.

Not only do the plants suffer dessication and structural damage from 120 MPH winds, but the leaves and stems are bombarded with high speed grit from dust and the roofs soil itself.

The woven mat provides significant support to the root system and stem and in my opinion is the reason the plants did not fly off the roof immediately.

Green Roof Plant Before Hurricane Testing


Green Roof Plant after 120 MPH winds for 3 minutes


We are analyzing what the test results and observations and will be providing additional comments.

More soon!

Happy green roofing and as always - email me with our questions.

Thursday, October 21, 2010

Green Roofs, Florida and Hurricane Wind Force Testing

Green roofs in Florida must be designed to withstand tropical storms and hurricane force winds.

Hurricane winds speeds can easily reach 130 mph.

Loose edges or other exposed corners, trays on a Florida green roof can be grabbed by the winds and flung across and off the building.

The photo below depicts the hurricane simulator at the University of Florida.  The system will be conducting a hurricane simulation test on a MetroVerde green roof panel.

Hurricane Simulator at UF - Testing MetroVerde Green Roof Panel


The tested panel is a mat based system.

We will be posting results soon.

As always, feel free to email us with your Green Roof or Green Roof Design questions.

Happy Green Roofing!

Kevin.