attaching solar panels

Almot wrote:
Colo, with a pair of 3" angle pieces you will have plenty of height adjustment. Having 3 pieces just doesn't make sense to me. Home Depot have a limited choice of aluminum stock, check Online Metals.

3/4" particle board is in fact 5/8", usual thing in lumber, "real" size is smaller than "nominal" size. Each single screw #10 provides very little grip, that's why with a big panel you need either more than 4 brackets or more than 2 screws per bracket, or hit the rafters. I tried hitting the rafters and used 4 screws per 4"x6" bracket - 4" aluminum angle 6" long, 1/4" thick. 4" angle was necessary to raise one panel to clear the plumbing vent. Another panel I could mount on 3" or 3.5" angle brackets. Each bracket is single piece, attached to the side of the panel using rivet nut.

My 65"x39" 250W panel is sitting on mere 4 brackets. Having more brackets would make tilting more difficult, and having smaller brackets and fewer screws would be dangerous on tilted panel in high winds. As it turned out, I didn't need tilting :). Had I used 6 or 8 brackets per panel, I wouldn't worry (too much) about hitting rafters.

there are 3 brackets 3" long on each side a total of 6 per panel, they have 2 screws #12 for each bracket for a total of 12 screws per panel. I will not tilt them. they are to be installed on the back half of the roof which is sloped to the back.

Colo, with a pair of 3" angle pieces you will have plenty of height adjustment. Having 3 pieces just doesn't make sense to me. Home Depot have a limited choice of aluminum stock, check Online Metals.

3/4" particle board is in fact 5/8", usual thing in lumber, "real" size is smaller than "nominal" size. Each single screw #10 provides very little grip, that's why with a big panel you need either more than 4 brackets or more than 2 screws per bracket, or hit the rafters. I tried hitting the rafters and used 4 screws per 4"x6" bracket - 4" aluminum angle 6" long, 1/4" thick. 4" angle was necessary to raise one panel to clear the plumbing vent. Another panel I could mount on 3" or 3.5" angle brackets. Each bracket is single piece, attached to the side of the panel using rivet nut.

My 65"x39" 250W panel is sitting on mere 4 brackets. Having more brackets would make tilting more difficult, and having smaller brackets and fewer screws would be dangerous on tilted panel in high winds. As it turned out, I didn't need tilting :). Had I used 6 or 8 brackets per panel, I wouldn't worry (too much) about hitting rafters.

I know, two posts in a row is just plain "piggy"!
Sorry 'bout that!
Will somebody explain how a "well nut" works in this application? I can understand, if you can reach the underside of the roof and push them through. Does the barrel expand like a plastic drywall anchor? I don't understand how this hardware is useful here.

Thanks!

I tried to do more than one quote, but the frustration level is over the top for this time of day, so I will just reply to the thread.

I'm glad to see this thread, cause I just mounted my 39" X 64" panel, at 42 lbs. I was not happy with the perceived lack of "bite" of the 1 1/4" stainless screws I used. I did what almot said, though. Put screws through a puddle of Dicor under bracket. I have two brackets per side (total of 8) with two screws per bracket.

I stayed close to the roof, per advice from a local service manager at RV repair place I trust. I may (?) install some kind of wind deflector on the front side of the panel, but the front bedroom vent partially deflects, now, so maybe not.

Best (most reassuring) comment was about "professional" installers. Granted, it's not their RV, but if it doesn't hold down, the customer will probably be bring it back. I know I would. They aren't going to spend the extra time to locate rafters, if it's not necessary.

I have some time (till Jun 6) to allow the Dicor to cure, so hopefully, by then, it will be adhered as much as it will. Time will tell, and you can rest assured, if something ($300) blows off, down the road, I will post to this thread about it!

Just my $0.02!

Almot wrote:

Colo Native wrote:

the flat bar is between the angle on the roof and the angle on the panel to raise it up a bit so it separates them by a 1" or so.

Now I understand. It's a 3-part Z-bracket.

You can make it simpler and more reliable, a 2-part:
2" angle on the roof, and another 2" angle upside down on the panel. Both angles are joined with machine screws and lock-nuts along the vertical surface. Or, better yet - a pair of 3" angle pieces, then you'll have more surface area on the vertical adjoining sides.

Online Metal Store - a source of aluminum angle of any size. They can cut it into short pieces for a small fee. Or cut it yourself, a hack saw will do.

You should really have a wider foot on the roof than 1" angle that you are considering. The wider the angle - the better seal with Dicor.

Yea it is kind of like a 3 piece z I wanted it that way in case I ever wanted to change the height. The angle is what I found at Home Depot it's 1 1/2".

Colo Native wrote:

the flat bar is between the angle on the roof and the angle on the panel to raise it up a bit so it separates them by a 1" or so.

Now I understand. It's a 3-part Z-bracket.

You can make it simpler and more reliable, a 2-part:
2" angle on the roof, and another 2" angle upside down on the panel. Both angles are joined with machine screws and lock-nuts along the vertical surface. Or, better yet - a pair of 3" angle pieces, then you'll have more surface area on the vertical adjoining sides.

Online Metal Store - a source of aluminum angle of any size. They can cut it into short pieces for a small fee. Or cut it yourself, a hack saw will do.

You should really have a wider foot on the roof than 1" angle that you are considering. The wider the angle - the better seal with Dicor.

Let me see if I can interpret: Angle pieces are mounted to roof. A flat bar is attached to these angles with the flat bar face positioned vertically. The additional angle pieces are attached to the frame and also to the vertical flat bar face. Do I have it correct?

On a previous question of how to transpose interior rafter locations to the topside: I located a rafter as one side of the framing of a vent. The decorative vent fascia covers this rafter bottom chord. Since I knew rafters were close to 16" on center and 1 1/2" W, I used this as the interval between rafter top chords. On the roof, I used a tape measure with end holding on the vent body, measured back from that 14 3/4" to mark rafter top chord centers. Sometimes, it helps to have been a framing carpenter, lol.

Since I have a sheet aluminum roof, I had no choice but to find the rafter locations. I used a different system of brackets by attaching a 2" x 2" x 2" U-channel on the roof. The solar module is attached to the U channel through angle piece on the frame and drilled holes in both with 1//4" pins. Pins are used to facilitate one axis of the four-way tilting mechanism.



Those U channels are attached through a piece of Eternabond tape, the aluminum roof skin, and through the rafter top chords with three #12 screws/channel. I sealed around the perimeter of the channels with Geocel 2300 sealant. The neat thing about attaching through Eternabond is that the tape seals the screw threads and also the top of the screw as they are driven.

Don't know if this video from Eternabond is still working but it shows the sealing of the fasteners. It is magic. Eternabond video

Almot wrote:
Still dark :).
3" long flat bar between brackets? On a big panel your brackets will be few feet away from one another.

the flat bar is between the angle on the roof and the angle on the panel to raise it up a bit so it separates them by a 1" or so.

Still dark :).
3" long flat bar between brackets? On a big panel your brackets will be few feet away from one another.

Let see if I can explain it better I used angle on the frame side and on the roof side with a piece of 3" long x 1 1/2" flat bar placed between the 2 angle brackets. I have tried to do pics before but doesn't work.