Re: [RE-wrenches] Attaching Array To or Through Ply

Ray Walters via RE-wrenches Fri, 31 Mar 2023 19:14:17 -0700

Chris, Jason, all;

I really like the idea of double clamping in serious situations. I wishwe had had this conversation about 2 months ago, before we installed 2more systems in Puerto Rico. I definitely would have suggested the teamtry that. Save it for next time, and hopefully we get a bit better withnew found idea on each install.


Thanks again for great ideas Wrenches,

Ray

On 3/31/2023 2:15 PM, Jason Szumlanski wrote:

Hi Ray,

I'm happy to have some confirmation from another major storm's impact.My father has a home in Dominica, which was hit by Maria with 165 mphwinds before it moved on to PR. He had a mixed bag of results withsolar panels (forget about the pole mounts I installed there over 20years ago!)

I was just reminded by your email about something I plan to try. Forpanels that are pitched on flat roofs, I am going to double up andinstall BOTH IronRidge CAMO and UFOs. With proper planning, it wouldbe pretty easy to install with UFOs first and then go back and snap inall of the CAMOs without much labor cost and an acceptable materialcost for the added peace of mind.



Jason Szumlanski
Principal Solar Designer | Florida Solar Design Group
NABCEP Certified Solar Professional (PVIP)
Florida State Certified Solar Contractor CVC56956

On Thu, Mar 30, 2023 at 9:45 PM Ray Walters via RE-wrenches<re-wrenches@lists.re-wrenches.org> wrote:


    Hi Jason;

    I was like you: thinking good ol' bottom mounting with SS hardware
    was the best.  All of us old wrenches were wrong.

    The top down mounting system is much stronger.  I've only had a
    handful of failures over 25 years, and all were bottom mounted. 
    The module completely ripped off the rack, leaving the stainless
    hardware, washers, etc with a thin sliver of module frame
    between.  For repairs, I come back and install 1/2" SS angle on
    the inside of the module frame to spread the load more. AND....on
    new installs, no more bottom mounting. If you compare today's
    modules with old 12v models from 20 years ago, you'll see: much
    thinner metal on the bottom frames now.

    Meanwhile I saw several systems survive Hurricane Maria in Puerto
    Rico: all top down mounting.  You are correct that the failures
    come from the modules themselves letting go, not the racking. 
    Either the wind itself is so strong as to blow the glass, then the
    frame looses its structure, or flying debris breaks the glass.
    There were some MW PV fields that got tore up pretty bad.  So no,
    ground mounts definitely can be destroyed. They had tornadoes
    moving inside of the hurricane, and you could see it in the
    damage, 50' wide strips of total carnage with undamaged modules a
    few feet away. Like you said, The storm has a mind of its own.

    As far as mid clamp T bolt failures, I can confirm that probably a
    majority are not installed correctly, especially Unirac, which are
    terrible to get the T lined up right.  I've done numerous
    inspections world wide, and a signifcant % of racking I looked at
    was NOT installed correctly.
    1) The Ts not squarely lined up with the rail,
    2) massive over torqueing, to the point the bolt can't be reversed
    3)  under torqueing, to the point the modules had slipped down a
    little.

    Most of these problems come from installing with an impact
    driver.  Impact drivers are a great tool (so is a hammer), but you
    got to know when and where to Not use them, too.  They're great
    for installing the lags and L feet, but then get that tool off the
    roof.

    Use an electric screw driver, socket wrench, or *drill with a
    clutch* set low to snug up the clamps, and then final torque with
    a torque wrench. Period.

    Ray Walters
    Remote Solar
    Former NABCEP 2004-2016


    On 3/30/2023 4:34 PM, Jason Szumlanski via RE-wrenches wrote:

    That would be great if it were possible! I'm not sure how you
    bottom mount a flush mount array. For a brief period many years
    ago, I was building solar trailers. I would bottom mount 4-6
    panel arrays on rails in my warehouse and then hoist them up and
    through-bolt the whole array on the top of a trailer. I wasn't
    about to allow a trailer going 80 mph on the interstate to have
    panels mounted on the roof with mid-clamps! I had no idea what I
    was doing, but I had enough sense to know that would have been a
    bad idea!

    I did provide feedback to IronRidge regarding a handful of
    failures from Hurricane Ian, but most of the issues we saw were
    most likely related to catastrophic module failure. After all,
    they are only tested to 5600 Pa uplift for even the best options
    we have on the market and 2400 Pa for some (which I refuse to
    use). The mid-clamp T-bolts tearing out of the rail are slightly
    concerning, but this was pretty rare, and honestly it could be
    related to installation torque issues, misalignment, or coupled
    with module failure. There was no widespread or definitive reason
    for rail failures at the clamp locations.

    I would suggest that FEMA's recommendation is overkill and not
    based on much science, but conclusions based on anecdotal
    information without statistical data. It should be scrutinized. I
    think it would be a good idea to consider bottom mount for ground
    racks and tilt mounts that allow it, but it's just not practical
    or possible in the vast majority of residential installation
    cases. On that note, I am not aware of any ground mount failures
    around here from Hurricane Ian except for submerged arrays that
    were washed away from storm surge (Yikes!). And the handful of
    failures that we observed were a drop in the bucket relative to
    the installed numbers here.

    One other thing. Wind direction, upwind obstructions/windbreaks,
    and luck have a huge amount to do with failures (of both PV and
    roofs themselves). These storms pick winners and losers. You will
    have ten houses in a row with pool enclosures mangled, and one in
    the middle that is unscathed. It's crazy to see. We have lots of
    gated communities with houses close together. When wind
    accelerates between houses, it can topple air conditioning units
    and pool equipment. If you look hard enough at where the wind was
    coming from and the surrounding area, you can really see how
    there are so many factors that come into play.

    Jason Szumlanski
    Principal Solar Designer | Florida Solar Design Group
    NABCEP Certified Solar Professional (PVIP)
    Florida State Certified Solar Contractor CVC56956


    On Thu, Mar 30, 2023 at 7:35 AM Christopher Warfel via
    RE-wrenches <re-wrenches@lists.re-wrenches.org> wrote:

        If you look at FEMA's design guide for solar installations in
        FL and the Caribbean, the recommended module to rail
        attachment method is back to using the attachment holes in
        the solar module.  Chris

        On 3/30/2023 5:56 AM, Jason Szumlanski via RE-wrenches wrote:

This thread has morphed into more than it started as, and
for good reason. I want to provide some practical/anecdotal
information, having just gone through arguably the most
catastrophic wind event in Florida's history (Ian) since the
boom in solar energy started, and another major wind event
(Irrma) just 5 years ago.

First, Aside from the Sunmodo and Quickbolt decking-only
products, I would check out IronRidge's new entrant into the
market, the IronRidge HUG. If you can't find info on it, ask
your distributor or IronRidge sales rep. They have data on
truss attachments and also missed truss installation
procedures. It's a unique approach to a dual-purpose
product, and they did a stellar job on the engineering
documentation in my opinion.

Ok, now let's get to my most important point. Due to
Hurricane Ian, the number of roofing PV attachments that I
have witnessed that failed due to fastener pull-out (mine or
competitors):

ZERO

The only building where we had any mounts fail was on a flat
roof with pitched panels and Anchor Products mounts on TPO
membrane, but the mounts themselves did not cause the
failure. The roofing system itself failed, causing a small
section of the PV system to fail. But even in that case, the
following applies...

The weak point in a well-designed and installed system is
not the fastener or flashing system. The module to rail
connection is where we saw failures. These failures fell
into a few categories:

* Windborne debris struck panel, panel frame failed, panel
popped out of mid-clamps.
* Catastrophic wind forces popped panels out of mid-clamps
(a good percentage of panels found INTACT and still
functional on the ground!) I suspect the panels became
covex in the wind, bending frames inward.
* Windborne debris struck mounting system components,
panel dislodged, often still on the roof suspended by DC
leads.
* Mid-clamp t-bolt tore out of aluminum rail channel
(IronRidge UFO, Unirac SM).
* Mid-clamp sheared off (Quick Mount QRail).
* Unexplained module detachment failures.

On 9/28/22, while I stayed up all night bracing myself
against my front door that I thought was about to fail, I
was imagining how many roof leaks my clients were about to
endure, and wondered about the efficacy of my business going
forward. Those fears never materialized. Aside from a
handful of minor panel dislodgements, there was no panic
following the storm (with respect to solar panels). The
bigger problem became all of the people needing to remove
panels for roof replacements, but PV panels largely
protected roofs in the areas where they were installed.
Sadly, the rest of the roof often did not fare as well.

Anyway, back to the decking attachments. I have been
skeptical of non-flashed products for comp shingle roofs for
a long time. My thinking is coming around, particularly with
the HUG (I trust IronRidge's testing regime). And sealants
have come so far. This method will remain up for debate
probably for a long time. Around here, I am pretty certain
these products will outlast the shingles they are placed
upon. We only get 15 years out of most shingle roofs around
here.

About the pull-out fears... Mine are gone. We have done many
flat roofs with long fasteners through steel decking or wood
decking. These screws are usually something like #15 XHD
screws in lengths from 5 - 12". Not a single failure. We
have also used Quick Mount QBase Low-Slope bases on pitched
tile roofs that were only screwed into decking with 4
fasteners each (due to horizontal truss transitions) in some
cases. Zero failures. But the most relevant attachments I
can think of that are germane to this discussion are the
many thousands of S-5 SolarFoot that we have screwed into
decking on 5V metal roofs around here. These have four
screws per attachment, and S-5 load tests show something
like 240 lbs of pull-out strength in OSB (adjusted for
safety factor). When engineered for our wind loads, we
usually get anywhere from 36-48 inch attachment spacing,
sometimes 24 inches in certain roof zones. Again, not a
single failure.

I have more solar installations on Sanibel Island and Fort
Myers Beach (Hurricane Ian Ground zero) than anyone. Many of
those have decking-only attachments, S-5 clamps, flat roofs,
or other attachments other than trusses. I can tell you
unequivocally that I trust decking-only attachments from a
pull-out strength standpoint. When properly engineered, with
cautious attachment spacing, these mounts work in both OSB
and plywood. Because of the inconsistencies in OSB, we
always err on the side of caution, if not in the
engineering, then in the installation, by installing more
attachments than prescribed. But the evidence is clear. It
works.

Caveat to the above: I have zero experience with snow or
seismic, and no experience on roofs exceeding 8:12
pitch, and few above 6:12.

And one more shout-out to S-5 clamps on standing seam roofs.
Aside from one minor failure of the roof metal itself, not
an S-5 failure, we had zero failures of S-5 clamps
attachments to report.

I hope this anecdotal information helps and sets some fears
aside. Please reach out to me off-list if you want any
specifics or details about our experience with catastrophic
wind events.

Sincerely,

Jason Szumlanski
Principal Solar Designer | Florida Solar Design Group
NABCEP Certified Solar Professional (PVIP)
Florida State Certified Solar Contractor CVC56956

On Thu, Mar 30, 2023 at 2:47 AM William Miller via
RE-wrenches <re-wrenches@lists.re-wrenches.org> wrote:

Friends:

Thanks for bringing up this scenario.

I have two problems with using a product such as the
easy-feet or other deck-fastened brackets, particularly
on a rigid foam-above-sheeting roof:

1.I worry about compression of the foam material over
time. This could leave a void under the bracket which
could lead to leaks or wobbly brackets.

2.I don’t believe in chemical solutions for sloped-roof
rain-proofing. By that I mean the use of caulks,
gaskets, etc. Since roofs were first thatched, the
overriding wisdom is that gravity is the only way to
reliably shed water. Overlapping, seamless material is
the only method to use. Caulks degrade, roof surfaces
become powdery, and the rafter is often under an
architectural feature or seam in the shingles.

I researched the PLP EZ foot back when the company was
DPW. The fasteners provided were not rated for the
application, according to the fastener manufacturer. If
you can match the fasteners to the decking and the
forces, then maybe you have a start to a mounting solution.

Whatever product you use, I would install it on a
section of flashing metal, lapped under the next course
up. The flashing gives a flat, seamless surface to
caulk or gasket to. The thicker and wider the flashing,
the more you distribute the downward force

applied to the bracket by weight and fasteners. Any
voids under the bracket will have an overlapped flashing
above it.

I hope these musings help you find a solution.

William Miller

PS: I have encountered this roof configuration a few
times on flat, built-up roofing (BUR
<https://homeinspectioninsider.com/built-up-roofing/>).
We have dealt with it by cutting through the foam,
installing blocking on top of the sheeting and having a
roofer feather the blocks into the roofing with cant
strips

<https://www.blueridgefiberboard.com/cant-strip-tapered-edge-smoothes-roof-drainage-slope/>.
A pitched roof is a different situation, however.

Miller Solar

17395 Oak Road, Atascadero, CA 93422

805-438-5600

www.millersolar.com <http://www.millersolar.com/>

CA Lic. 773985

*From:*RE-wrenches
[mailto:re-wrenches-boun...@lists.re-wrenches.org] *On
Behalf Of *August Goers via RE-wrenches
*Sent:* Wednesday, March 29, 2023 11:47 AM
*To:* RE-wrenches
*Cc:* August Goers
*Subject:* Re: [RE-wrenches] Attaching Array To or
Through Ply

We've found that in the Bay Area that deck-mount
solutions typically pencil out structurally (via a
structural professional engineer) as long as the deck is
1/2" plywood or thicker, assuming we have all the info
on how the roof is constructed. The big assumption is
that we can get all that roof construction info, which
can be difficult for existing structures.

We haven't taken the plunge yet on the flahingless deck
mount products like the Sunmodo Nanomount or Unirac
Flashloc Duo. I do think that they offer several
significant advantages including not needing to find
rafters, thus virtually eliminating missed pilot holes,
and not disturbing the comp shingle by eliminating
prying up the courses to insert the flashing.

August

Luminalt

On Wed, Mar 29, 2023 at 11:34 AM Solar Energy Solutions
via RE-wrenches <re-wrenches@lists.re-wrenches.org> wrote:

We like Spider Rax… with the flashing!

*Spider-Rax PV Solar Mounting <https://spiderrax.com/>*

*spiderrax.com <https://spiderrax.com/>*

*Error! Filename not specified.*
<https://spiderrax.com/>

*Andrew Koyaanisqatsi*

President

*Solar Energy Solutions, Inc.
/The BRIGHT CHOICE/*

*Since 1987, helping you and your *

*Portland neighbors move towards an environmentally
sustainable future.*

*503-238-4502 <tel:503-238-4502>
www.SolarEnergyOregon.com
<http://www.solarenergyoregon.com/>*

On Mar 29, 2023, at 11:04 AM, Jerry Shafer via
RE-wrenches <re-wrenches@lists.re-wrenches.org> wrote:

Wrenches

Sounds like a SIP's type product, there are
quite a few multi hole attachment bases that are
designed for SIP's. Most will have a larger
base, lots of holes for screws to attach that do
not require rafters underneath to attach.

Fun times

On Wed, Mar 29, 2023, 8:30 AM frenergy via
RE-wrenches <re-wrenches@lists.re-wrenches.org>
wrote:

Matt,

I guess my questions are 1/2"
plywood or 5/8" and how thick is the foam?
Oh and I assume its nominal 2X6 T&G? Do you
know how the plywood is
attached?.....through the foam into the
T&G?... to stringers, nailers or whatever
they're called?

Bill

Feather River Solar Electric

Bill Battagin, Owner

4291 Nelson St.(shipping)

5575 Genesee Rd. (USPS, UPS)

Taylorsville, CA 95983

530.284.1925 Office/ 530.258.1641 Cell

CA Lic 874049

Solar powered since 1982

On 3/29/2023 7:53 AM, Dave Tedeyan via
RE-wrenches wrote:

Hi Matt,

I've used these in the past when on a
comp roof and there was no good way to
get into the rafters (or TJI's in this case)

https://sunmodo.com/nanomount/

You might want to replace the screws
with something shorter and beefier
though to get more grip if you are only
going into 1/2" plywood.

Cheers,

Dave

On Wed, Mar 29, 2023 at 10:38 AM Matt
Sherald via RE-wrenches
<re-wrenches@lists.re-wrenches.org> wrote:

Hi All,

I've run into a roof-mounted job
where the roof is built-up with the
following:

Comp shingle

Plywood

Foam board

T&G (roof deck, but also interior
ceiling)

The beams that hold the t&g up are
wide-spaced and not convenient for
fastening the full extent of the array.

This being the case, I was
considering other fastening options
and am writing to pick the
collective brain of the Wrenches to
see how others have addressed
similar situations.

One thought I had was to use the PLP
Easy Mounting Foot and I'd be glad
for any opinions on that or another
solution.

-Matt

--

                                Matt Sherald

                                PIMBY Energy, LLC

                                304-704-5943



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                     ENTECH Engineering, Inc.
        PO Box 871, Block Island, RI 02807
                            401-466-8978
        <http://entech-engineering.com>


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Re: [RE-wrenches] Attaching Array To or Through Ply

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