Standing Seam S5s vs. Penetrations [RE-wrenches]

[Kelly Keilwitz]

Hi Jeff, 
We designed a 21.3 KW PV system with S-5! clamps that was recently installed
(another company won the install bid) on a remodeled barn-turned research
center (State project). The design used top-down rails mounted to the S-5!
clamps.

I worked extensively with Rob Haddock of S-5! and learned a lot during the
design process. Here's some points:

- The clamps will hold the PV array to the roof just fine - we need to worry
about how the roof is attached to the building. I.E. The clamp number will
be determined by how the load is distributed over the roofing rather than
the load capacity of the clamp.

- In general, put the S-5! Clips on the same attachment frequency as the
roof-to-building clips or screws. That means you need more S-5! clips for
thinner gauge roofing attached along seams 12" OC than thicker structural
roofing attached with clips every 3 feet.

- The potential wind uplift on the array will be approximately the same as
what the wind uplift on the roofing would be without the array over it.
Again, evenly distributing the load over the roofing is important.

- Work closely with the roofing company structural engineer (if a new
installation), or find the engineering data for the existing roof.

- The shape and type of seam is important in determining the type of S-5!
clamp used. 

- S-5! clamps are very expensive. If the number of clamps in your design is
way more than you need for clamp-to-roofing capacity (which it probably will
be) you can save over half the cost by using the S-5! "Mini" clamp. Sunwize
just sourced some for us for a small job at $6.75 each.

-Kelly

Kelly Keilwitz, P.E.
Whidbey Sun & Wind, LLC
Renewable Energy Systems
NABCEP Certified PV Installer
987 Wanamaker Rd, 
Coupeville, WA 98239
PH & FAX 360-678-7131
sunwind at whidbeysunwind.com
 


On 9/11/06 5:14 PM, "Jeff Clearwater" <clrwater at earthlink.net> wrote:

> 
> Hi All,
> 
> We have a commercial client with a Starshield Standing Seam roof that
> would love to see us not have to do penetrations.
> 
> The word around seems to be that the Standing Seam numbers do show
> sufficient uplift capability when one does the engineering as long as
> it's installed right with the right number of screws/purlings.   We
> have an engineer about to look at that.     However some installers
> and racking companies say they just have to avoid it altogether for
> liability reasons.
> 
> I know we've had some discussions before on S5! and some case
> histories - but I just wanted to make sure I wasn't wasting my
> engineers time.
> 
> How many of you have actually installed S5! clips AND gotten an
> engineering stamp that they work?  Any problems with S5!
> installations thus far?  Any pointers on what the real issues were in
> order to get that stamp?  What are they looking for specifically?
> 
> Any experiences you may have had might save me some time and money.
> 
> Thanks!
> 
> Jeff C.
> 
> 
> 
> 
> 


 


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