In high uplift scenarios, I have used both IronRidge Camo clips on the bottom frame of the module and UFO clips on the top. More expensive, but definitely an all around rock solid approach.
-Chris 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. >>> >>> >>> >>> Wm >>> >>> >>> >>> Miller Solar >>> >>> 17395 Oak Road, Atascadero, CA 93422 >>> >>> 805-438-5600 >>> >>> 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 <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 >>> <https://www.google.com/maps/search/5575+Genesee+Rd?entry=gmail&source=g>. >>> (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 >>> >>> >>> >>> >>> >>> >>> >>> _______________________________________________ >>> List sponsored by Redwood Alliance >>> >>> >>> >> _______________________________________________ >> >> >> -- >> Christopher Warfel >> ENTECH Engineering, Inc. >> PO Box 871, Block Island, RI 02807 >> 401-466-8978 >> <http://entech-engineering.com> >> >> > _______________________________________________ > List sponsored by Redwood Alliance > > Pay optional member dues here: http://re-wrenches.org > > List Address: RE-wrenches@lists.re-wrenches.org > > Change listserver email address & > settings:http://lists.re-wrenches.org/options.cgi/re-wrenches-re-wrenches.org > > There are two list archives for searching. When one doesn't work, try the > other:https://www.mail-archive.com/re-wrenches@lists.re-wrenches.org/http://lists.re-wrenches.org/pipermail/re-wrenches-re-wrenches.org > > List rules & etiquette:http://www.re-wrenches.org/etiquette.htm > > Check out or update participant bios:http://www.members.re-wrenches.org > > _______________________________________________ > List sponsored by Redwood Alliance > > Pay optional member dues here: http://re-wrenches.org > > List Address: RE-wrenches@lists.re-wrenches.org > > Change listserver email address & settings: > http://lists.re-wrenches.org/options.cgi/re-wrenches-re-wrenches.org > > There are two list archives for searching. 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