[RE-wrenches] Ground mount fire code clarifications

[Dan Fink]

Hello esteemed Wrenches; I am trying to clear this up for a client and his
AHJ, which is also puzzled at how to interpret IFC 2018, Section 1204.4,
which states:

Setback requirements shall not apply to ground-mounted, free-standing
> photovoltaic arrays. A clear, brush-free area of 10 feet (3048 mm) shall be
> required for ground-mounted photovoltaic arrays.


I found one lone informational note in a white paper stating this was to
prevent a burning PV array from igniting surrounding vegetation and the
fire spreading.

So, has anyone dealt with an AHJ on this before? Our questions are:

   - What exactly is a "free-standing photovoltaic array" that is exempt? A
   pole mount? Couldn't burning debris from that ignite vegetation underneath?
   - What exactly does "A clear, brush-free area of 10 feet (3048 mm)"
   mean? "10 feet" is a linear measurement, not an area, that would be in
   square feet.
   - What is "brush"? Does grass count as brush?

I would interpret this on the safe side as meaning that all vegetation
under the PV array and out to a 10 foot perimeter should be cleared, except
for pole-mount arrays (that exception makes no sense to me).

I always recommend to clients that the area *under* the ground mount array
should be pea gravel bordered by railroad ties, but out to 10 feet from the
array edge seems excessive.

Any input greatly appreciated!

Dan Fink
Executive Director, Buckville Energy Consulting
NABCEP PV Associate
NABCEP Certified PV System Inspector
IREC Certified Instructor™ for:
~ PV Installation Professional
~ Small Wind Installer
NABCEP Registered Continuing Education Providers
d <dan.fink at greendustrialtraining.com>anbob88 at gmail.com
970-672-4342
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