Lapping PV panels to create water shedding roof. Thoughts? Comments?

[galstaf]

The issue I see with this is 1) having to cut it, unless one can find the right width, 2) how to bridge the x and y axis, 3) not sure it will hold in all environments, 4) wide variation in qualities as some rolls hold up well and others don’t. I use this product around windows and doors, but sometimes it has to be stapled to hold. The thin aluminum HVAC tape would likely hold better to aluminum frames, in my experience, but getting the right width may be the hard part.

Hey JC,

The HVAC tape is sticky as hell... do you think it would hold up tho in the elements?
BTW I am in the Atlanta area... so *very* north Florida ;-)
However I do go down to Jacksonville a few times a year, so maybe I could swing by your barn supply shop. Who do you recommend?
Thanks again!

 

[JCSchwarb]

Hey JC,

The HVAC tape is sticky as hell... do you think it would hold up tho in the elements?
BTW I am in the Atlanta area... so *very* north Florida ;-)
However I do go down to Jacksonville a few times a year, so maybe I could swing by your barn supply shop. Who do you recommend?
Thanks again!

based on this thread, I ordered a few Aluminum HVAC generic rolls on Amazon. I don’t have a local barn supply shop, mostly buy online or Lowes… Will report back on how they hold up in the rains. Based on my experience with aluminum tape on aluminum, it should hold pretty well.

 

[OffGridForGood]

Hey OGFG... Any recommendation of a specific type or brand? Have you used it yourself? Cheers!

I have used this product for decades.
Recently built a Pergola over our deck using glass (from a project where we were replacing perfectly good glazing skylight) and I used Butyl tape for all the glazing. No leaks.
The comment about butyl failure if left exposed to sun is true. If you want the sealant left exposed to direct sun and weather, it will not last. It is intended to be sandwiched between the glass and a pressure cap and not left exposed.
Tremco make a number of grades.

 

[12VoltInstalls]

Suggested brand that you have had success with?

3M 5200 is the gold standard but somewhat expensive. The loktite product is what I’ve been using and pushing the limits of for a million years because it’s somewhat inexpensive.

 

[galstaf]

@JCSchwarb

This is what I was asking about from your post on page 2.. which company was this?:


"If you are in north FL I can point you to an excellent company, otherwise suggest looking for pole barn supply company close to you. They will provide everything including posts, metal trusses and 2x6” PT. If you wanted more energy under the panels, you could add 2x4” stand-off at every edge where panels sit. Would be fast and easier to install panels and protect underwrap."

 

[Hedges]

Flashing wise, something like this is what I had in mind.. kind of a T-shape rigid flashing that could be screwed thru to hold the PV panels in place and be sealed along the underside edge.

I just don't know what to search for to find a product like this. Can anyone suggest something that could work that would push the water back onto the panel and stop it leaking thru.

There was a company on the internet that made that sort of seal for solar panels. They were used on a couple of high end architectural wonders. I expect the company went out of business after the inevitable lawsuits. Its tough application especially at corners.

I would think a bellow type seal with a thin piece of flashing bent in sharp upside down "V" The two pieces of the V would be attached to the adjoining side rails of the panels and then a poly sealant bead would be run down the seam between the metal and the frame.

BLIKIR Solar Panels Gap EPDM T-Gasket Water Seal Strip 55 Meter Reel | eBay

The width of the main T leg is 2.5mm.

www.ebay.com

Years ago, GE bought Astropower's assets and made a "tile" out of framed panels.

A different frame edge on two sides could overlap next lower panel without as much height. Custom extrusion, or an angle aluminum epoxied to two edges of standard panel. But I'd rather it overlapped in a manner such that water couldn't get between glass and aluminum, and back up.

I think on corner, "diamond" rather than portrait or landscape would be better orientation.

Maybe find a way to do it with two edges of frame removed.

 

[galstaf]

BLIKIR Solar Panels Gap EPDM T-Gasket Water Seal Strip 55 Meter Reel | eBay

The width of the main T leg is 2.5mm.

www.ebay.com

Years ago, GE bought Astropower's assets and made a "tile" out of framed panels.

A different frame edge on two sides could overlap next lower panel without as much height. Custom extrusion, or an angle aluminum epoxied to two edges of standard panel. But I'd rather it overlapped in a manner such that water couldn't get between glass and aluminum, and back up.

I think on corner, "diamond" rather than portrait or landscape would be better orientation.

Maybe find a way to do it with two edges of frame removed.

I will post the eBay before it expires and makes a dead link. Thanks for that one! How does the EPDM hold up? Have you personally tried this stuff by any chance?

 

[galstaf]

Years ago, GE bought Astropower's assets and made a "tile" out of framed panels.

A different frame edge on two sides could overlap next lower panel without as much height. Custom extrusion, or an angle aluminum epoxied to two edges of standard panel. But I'd rather it overlapped in a manner such that water couldn't get between glass and aluminum, and back up.

I think on corner, "diamond" rather than portrait or landscape would be better orientation.

Maybe find a way to do it with two edges of frame removed.

Hey @Hedges .. Not sure what you mean by this tho. Do you have any pics to better demonstrate what you are talking about?

 

[Hedges]

I will post the eBay before it expires and makes a dead link. Thanks for that one! How does the EPDM hold up? Have you personally tried this stuff by any chance?

Haven't tried, just bookmarked it.

Hey @Hedges .. Not sure what you mean by this tho. Do you have any pics to better demonstrate what you are talking about?

I'm imagining panel rotated to resemble these tiles:

Maybe remove two sides of the frame, except then glass would slip out.
Maybe cut the two sides so they are only 3/8" or so tall, overlap next panel without such a tall step?

 

[galstaf]

Haven't tried, just bookmarked it.



I'm imagining panel rotated to resemble these tiles:

Maybe remove two sides of the frame, except then glass would slip out.
Maybe cut the two sides so they are only 3/8" or so tall, overlap next panel without such a tall step?

Interesting idea, but seems like a boat load more work tho! Cutting Aluminum sucks because it is so soft and grabby. Also, wouldn't cutting the frame severely compromise the rigidity and toughness of the panel? Plus potentially it's water tightness?

Plus don't you think rectangular panels would look weird rotated 45 degrees?

Have you tried anything like this?

 

[SolarRich]

As was mentioned....
I used aluminum tape from Home Depot to seal the joints between panels on my trackers. The tape lasts for about 10 years and is easy to re-apply.
Did this to keep water off the bearings and other parts that were suffering due to water exposure.

 

[Hedges]

Only in my head.
Cutting on a band saw would be easy.
You can probably tile with whole panels (intact frames), but the step would be taller.

Weird? You guys who worry about appearance are weird. Form follows function.
If you place them in landscape orientation, water can run under an edge running down the fall line, and drip inside.
Placed as a diamond, drips traveling downhill are always away from an edge. Should shed water much better, without relying on caulk to keep things dry inside.

 

[JCSchwarb]

@JCSchwarb

This is what I was asking about from your post on page 2.. which company was this?:


"If you are in north FL I can point you to an excellent company, otherwise suggest looking for pole barn supply company close to you. They will provide everything including posts, metal trusses and 2x6” PT. If you wanted more energy under the panels, you could add 2x4” stand-off at every edge where panels sit. Would be fast and easier to install panels and protect underwrap."

So sorry my friend! Senior moment… here it is; https://www.backwoodsbuildings.net/ they are in Chipley, FL 32428.

James will hook you up. Awesome family man and he is sharp and super helpful. Hope that is helpful for you. Let me know if you have any Pole Barn questions as I have built a few.

-Jay

 

[galstaf]

So sorry my friend! Senior moment… here it is; https://www.backwoodsbuildings.net/ they are in Chipley, FL 32428.

James will hook you up. Awesome family man and he is sharp and super helpful. Hope that is helpful for you. Let me know if you have any Pole Barn questions as I have built a few.

-Jay

Ha .. no worries. I get my share of senior moments too, but I pretend it is "Long COVID".
I see Backwoods Buildings are on the PC Beach side. I will have to coordinate it with a trip down there.

I definitely recognize their look in your PV structure!



I will have to hit you up on the pole barn ideas ... I have inherited a number of super tough and quite heavy polyethylene service lines (about 20 feet long and 16 inch diameter). I was thinking they could make a pole barn that no insect wants to eat. It will be a little unique, but I think a creative way to use the pipes other than burying them as culverts.

 

[12VoltInstalls]

shed water much better, without relying on caulk

Spoken like an engineer or something

Form follows function

Wasn’t one of the biggest problems with rooftop solar when it first came out… appearance? Then they marketed the greeny save the planet aspect and it lost its stigma when it transitioned to virtue signaling. By probably 2010 or so it was a nonissue.

It’s merely an intellectual resistance due to observations of perceived ‘normal’ 90* panel arrangements to be concerned with 45* orientation imho; no less or more weird than panels on a roof to begin with.

 

[Hedges]

The Solar Shingles and Tiles I see on a few houses around me are nicer looking.
I think they are generally less efficient (run hotter) and if thin-film won't have as long lifespan.

We see calculations of how much value panels add to a house. That might be the case for a business where cash flow is often considered.
On a nice house, if facing the street, conventional panels are ugly. I haven't seen anything demonstrating they don't actually reduce selling price.
A $5 ~ $15k PV system on a $2M ~ $3M house.

 

[JCSchwarb]

The Solar Shingles and Tiles I see on a few houses around me are nicer looking.
I think they are generally less efficient (run hotter) and if thin-film won't have as long lifespan.

We see calculations of how much value panels add to a house. That might be the case for a business where cash flow is often considered.
On a nice house, if facing the street, conventional panels are ugly. I haven't seen anything demonstrating they don't actually reduce selling price.
A $5 ~ $15k PV system on a $2M ~ $3M house.

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We learned the hard way in San Diego, on a leased 8kWh system, no one wanted to buy the house. Many deals fell through as a result. It was very counterintuitive to us why no one wanted to inherit the leased system. I am not a fan of solar panels on shingle roofs, mainly due to texture and color contrasts and maintenance issues. For a high end house, I would want a metal or tile roof that will outlast the panels and blend in better. Ideally a porch trellis is my favorite design choice and is what I used on my latest installation. It needs to look purposefully and that picture above does not look purposeful to me, but rather haphazard.

 

[galstaf]

We learned the hard way in San Diego, on a leased 8kWh system, no one wanted to buy the house. Many deals fell through as a result. It was very counterintuitive to us why no one wanted to inherit the leased system. I am not a fan of solar panels on shingle roofs, mainly due to texture and color contrasts and maintenance issues. For a high end house, I would want a metal or tile roof that will outlast the panels and blend in better. Ideally a porch trellis is my favorite design choice and is what I used on my latest installation. It needs to look purposefully and that picture above does not look purposeful to me, but rather haphazard.

Agreed... looks like crap .. esp. on a high end house.
Also complex steep pitch roofs are generally less than ideal angle wise and orientation wise.

Also in my case the buildings are just poorly situated in the shade for a lot of the year, so paneling the roof would be a waste of 90% of the panels production capability.
Much better to do auxiliary buildings like your pole barn that are built with solar production in mind. Perfect roof pitch and orientation. Shallower pitch for easier maintenance.

 

[JCSchwarb]

Agreed... looks like crap .. esp. on a high end house.
Also complex steep pitch roofs are generally less than ideal angle wise and orientation wise.

Also in my case the buildings are just poorly situated in the shade for a lot of the year, so paneling the roof would be a waste of 90% of the panels production capability.
Much better to do auxiliary buildings like your pole barn that are built with solar production in mind. Perfect roof pitch and orientation. Shallower pitch for easier maintenance.

You raise a good point. Try working on a second story and steep 6/12 or more pitch. No thanks. Removing for a reroof costs thousands on top of the roof costs. Wonder when architects and builders will take this into consideration? Perhaps all in one solar roof tiles will become the norm.

 

[gramos100]

Or could the flashing be skipped.. push the panels closer together and would a silicon sealant suffice?
How much would the panels shift around due to weather and temperature?



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Butyl rubber strip between all mating faces , some are even self adhesive, from glazing suppliers ,