In response to your your call of .... I now submit....
As you can see from the date on this post ( 26th September) my ball has been over in the City Building Department court since July. Almost 3 months. And I have yet to win the match.
There have been several rounds of phone calls, rejections, questions, re calculations and re submissions - the most recent one was the fifth. I have moved forward slowly and we are now addressing what is, I hope, one last and final "concern".
It's all about wind uplift. And a "Canadian" procedure.
All my spare time has unearthed only one procedure to manage wind uplift and sedum mats, short of heading into the wind tunnel and generating yet another thesis.
It is based on a report prepared by WSG Engineering, Aachen, Germany. The WSG analytical report entitled “Assessment of positional security against wind uplift for a roof planting system that is permeable to wind” was issued in November, 1999. I understand that this work was funded by XEROFLOR and it is based on some of their sedum mat products.
It acknowledges the porosity of the sedum mat and uses a moderating factor to conservatively calculate the actual uplift load. Given my own reluctance to anchor the mats through my single membrane roof, I am relying on the weight of the mat to counteract any uplift.
Several examples of it application have been provided to the City, including one down on Elm St, Toronto. We even provided that name of the City official who has accepted the procedure on another local roof.
To no avail.
I am obliged to engage yet another engineer just to sign-off on the wind uplift component of this project.
When will it ever end?
I just hope I can get my own roof on before this winter hits and before the XERO-FLOR / NRC work hits the printers press.
