[RE-wrenches] PV wind load

[William Miller]

Rebecca:

It sounds like you have made an air-tight case (pun intended) and you have 
still not been able to convince this thick-headed inspector.  I have had a 
similar experience last summer that might be relevant:  After being pushed 
around beyond my patience, I fought back.  I worked up the chain of 
command, stayed professional and put it all in writing.

I won the battle and set a precedent.  I have forbidden the building 
department from assigning the problem inspector to my projects and, to my 
amazement,  the department obeys my request!

Good luck, and let us know how it turns out

William Miller



At 05:55 PM 12/4/2009, you wrote:
>Solar is somewhat 'new technology' where I live. :-) I have a building 
>inspector that feels that (32) Sanyo modules (6.88 kW array) mounted to a 
>house roof is going to cause undue stress to the roof truss (it is a 
>regular house in a Minnesota suburb, building height is 26', 30 degree 
>roof angle, in a suburban neighborhood. 2" x 4" manufactured truss). We 
>are leaving 12-24" on each edge with no PV, and are careful to attach to 
>the center of each rafter.
>
>The inspector is not that concerned with dead load, but is especially 
>concerned with wind load. We have provided an engineering letter that 
>ascertains that a solar array mounted parallel to the roof surface is well 
>within the parameters of what a typical roof truss can handle. We were 
>required to have an engineer look at this address specifically, so we then 
>provided an additional engineer's letter that affirmed that yes, solar 
>mounted in the manner we proposed (with Quick-Mount attachment and Unirac 
>SolarMount rails, all installed according to manufacturers' instructions) 
>would be fine on this home. The building inspector insists that the wind 
>load is excessive, and wants more analysis. Do any of you have ideas, 
>experience, or data that might help me?
>
>Rebecca Lundberg
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