[RE-wrenches] Flat Roof PV Attachments with Tapered Insulation

[August Goers]

Jason,



It's funny that you bring this up because it is an issue that we constantly
face on commercial new construction. Commercial roofers want 8" plus for
their lead jacks plus the cricket often takes several inches above the
deck.



Many folks in the Bay Area are using Hollaender rail fittings with
galvanized steel or aluminum pipe. The advantage is that you can cut the
pipe as long as needed. The entire setup is very robust but a bit costly.
Here's a link to various types of flanges they offer:



http://www.hollaender.com/?page=flanges



And here's a solar-specific link:



http://solar.hollaender.com/



I'm looking forward to seeing if anyone else knows about off the shelf
longer stanchions. Unirac used to make custom longer lengths of their steel
standoff but no longer offer it.



Best,



August





*August Goers*

Luminalt Energy Corporation

o: 415.641.4000

m: 415.559.1525



*From:* re-wrenches-bounces at lists.re-wrenches.org [mailto:
re-wrenches-bounces at lists.re-wrenches.org] *On Behalf Of *Jason Szumlanski
*Sent:* Tuesday, September 10, 2013 1:27 PM
*To:* RE-wrenches
*Subject:* [RE-wrenches] Flat Roof PV Attachments with Tapered Insulation



Let me start be saying that I'm talking about mechanically attached
tilt-mount solutions capable of handling 172 mph design wind speed, ASCE
7-10. Ballasted systems need not apply.



We've used a variety of hardware for TPO membrane flat roofs, which is
becoming more and more popular around here. We've found that hardware bases
that mount on top of the membrane work well when there is a single slope in
the array area and the rails can follow the contours of the roof surface.
Ecofasten base plates spread the load out enough onto a DeskDeck roof board
or similar, and have proven to be pretty versatile.



However, when you have center drains or other situations with multiple
slopes, it is advantageous to attach to the roof deck directly, typically
plywood here, particularly in new construction. Tapered insulation,
decking, and membrane can be cut around stand-offs and flashed nicely with
8" TPO boots. This keeps rails parallel to the trusses/ground, and
disregards the roof membrane slope. The problem with this is that
insulation can easily get to be 6" thick, even on a small residential flat
roof, requiring a minimum 14" long stand-off to fit a standard TPO boot
above the membrane.



Long story short, what mounting systems are others using for this scenario,
and who offers long stand-offs?


J

ason Szumlanski

Fafco Solar
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