Mounting solar

[waynefi]

For those of you with rooftop solar, how do you mount the panel to avoid leaks?

How do you route the cable?

Where do you put the controller?

Where does it actually wire in (which side off the cutoff switch)?

I have a suitcase solar panel, which avoids all these questions.

[bpounds]

If you tape your panels to a rubber roof, it will only be as secure as the glue that holds the rubber roof to the sheathing. I would not trust it. I've seen too many posts from folks dealing with ballooning roof membranes.

I used the Renogy mounting brackets. They are sheet aluminum formed into a Zee shape. 4 brackets per panel. I layed down a generous amount of dicor, placed the Zee foot on the Dicor, screwed them down making sure at least 1 screw per bracket hit a rafter. Then covered the screw heads with more Dicor.

The only problem I have with the Zee brackets is that you cannot get the panels lifted up without pulling them up off the roof. And they are glued down hard, and I would probably damage the rubber roof trying to get them loose. If I ever have to do this, I will simply cut the vertical leg leaving most of it standing up from the roof. Now it is an L bracket, still screwed and glued. Then I would make some more L brackets to attached between the standing leg and the panel. Which is what I would do from the getgo if I was doing this again. I may never have to lift a panel anyway, so may not ever be any issue. I am confident that the brackets will outlast the roof membrane and never leak.

For the cable I simply drilled a hole through the roof down into an interior wall. Fed my cable through and then sealed the hole with Dicor, building it up as a flashing. I did not see any need for any J-box or actual flashing. It's only about a 5/8" diameter hole and is easily sealed with the caulk. I used the type of cable that is a red and black conductor in an outer UV rated sheath. Not individual conductors. I left about 3' of the cable above the roof line, formed it into a drip loop just above the Dicor pyramid, and then assembled my MC connector. From there it is extension cables that I made up in whatever lengths needed to go between panels. Extensions cables are extremely easy to just make up whatever you need.

All the cable inside is within walls. Pretty easy to fish it down to the basement, which is where the controller lives.

Like others, I used some Eternabond tape and some Dicor blobs to secure the cables to the roof, just enough to keep them from flopping around and grinding away at the rubber roof.

[ajriding]

The no-holes-in-roof concept is to minimize possible leaks. One drip in one hole once per day will rot out a ceiling. It is easy to prevent and seal the hole, yes, but also easy to miss one little crack. More holes = more potential.

On another note…
I trade campers almost every year, for the past 4 years I have had 4 campers. I do not get to see the long-term effects of my upgrades.
I have used both flexible (very thin, can be taped flat to roof), and aluminum glass framed panels.
The flexible ones are meant to be adhered flat to the roof and thus not intended to have airflow under. Has anyone had these for many years with no "over heating" or damage due to lack of air?

I had one flat panel go bad. Not sure if from a tree limb falling on it or what, I assume a connector inside became broken. $179 panel at the time (now $149 - expensive compared to glass, but for me worth a few extra bucks to be flat, aero and sleek.

[BruceMc]

I mounted the panels on our previous motorhome rubber roof using angle aluminum, then run the leads through a weathertight connector into a hollow aluminum framing member.

Pics:

Framing dicor'd and screwed to the roof:


Weather-tight connection into framing member:


Remainder of Solar Panel Install images

I've yet to add solar to the new Sunseeker (irony not intended), but it's in the plan.

[TomG2]

I went with the "No holes" plan for several reasons. I trade trailers often and do not like trying to convince buyers that, "Yes, those are holes but they will never leak". I tried leaving the panels on but hated to see the money pull out of the driveway with the trailer. I also thought how nice it would be to remove the panels if parked in a shady spot. (The last never happened.) Fairly easy to remove and store panels if a hail storm is imminent. That has happened.

[CA_Traveler]

I've never understood the reluctance to drill holes in the roof given that the mfg has already drilled hundreds...

Of course if not sealed correctly then best to not drill holes.

Click for my install. My panels are raised to clear roof obstacles and avoid shadows from the AC's.

Hollow inside walls are often a good choice for running wires from the roof. For mine I removed the inside panels from a cabinet resulting with no wires visible.

[deltabravo]

Here's my solar insallation

Dicor under the mounts, mounts screwed to roof, Dicor over the mounting feet / screws.

[marcsbigfoot20b]

VHB taped my 2 180 watt panels brackets to the rubber roof, I also tilt them. No problem, just prep the surfaces.
They have survived multiple 85-90 mph runs not including headwinds.
Actually I think they might be problematic removing the brackets from the roof, they stick so good.

[agesilaus]

Yeah as I understand it, the panels are supposed to have ventilation space between the panel and roof. A 1/2 inch or so is plenty. But you need some, I suspect mounting directly on the roof, besides the effect on the roofing may decrease the lifespan of the panel from being over heated.

[2oldman]

ajriding wrote:
Tape it on! Do not put holes in your roof.

Everyone has his or her level of comfort, so I guess you're in the 'not comfortable' zone with drilling holes.

It's not a big deal if you do it right. I've had panels up there for 15 years without a single problem, and that's with 50 holes!

Flexible panels get very hot, and I do not want all that heat directly on the surface of my rubber roof. I also tilt my panels - ain't gonna happen with tape.

As said above, I don't want tape on my rubber roof.

[SpeakEasy]

Yeah. Depends on the type of roof.

On mine, it's #10 screws (into aluminum frame members where I could) and dicor.

Cable routed through the fridge vent.

Controller mounted inside above the fridge.

-Speak

[time2roll]

Tape is great to a solid surface such as fiberglass or aluminum.
I would not trust tape on my rubber roof.

[ajriding]

You might think I am kidding, but this is real:

Tape it on! Do not put holes in your roof.

Do you have flexible panels or aluminum frame ones?

For the thin flexible ones you can use 4 inch EternaBond tape and simply tape them down, half on the panel and half on the roof. Clean roof so tape makes a good bond.
This will hold. You can remove the tape, and is easier by heating it up, but it still has a good gooey grip.
Be careful with the tape and inside corners, put plenty of slack into the corner so tape does not pull up in the corner.

For a frame use VHB tape.Very High Bond tape. I use an aluminum bracket, L-bracket. Tape this to the roof and bolt the panel to the bracket. My current bracket is about 5 inches at each corner (5 inch by 1 inch taped down).
It might be easier to bolt first, then tape everything down together so you do not mess up the placement of the brackets. The tape is not meant to be removed.

I have driven thousands and thousands of miles with each method with no issues, and no tape losing hold

[agesilaus]

Well nuts would take a much bigger hole in the roof. Not a very good idea in my estimation.

[bdhoun]

I was researching this topic yesterday as I just bought our 1st 100W panel. I watched a youtube video from a guy suggesting to use well nuts. Looks like a fantastic way to do it.