Solar Panels on Open Porch Canopy

[dhoward26]

Just had an interesting job come in that I haven't seen before.

A guy that installs solar panels wants to install them on the structure in the picture attached. My first thoughts on wind loading are to treat each solar panel as a sign...makes sense to me. Earthquake is decently straight forward. I'm pretty sure I will have to either replace or add some joists to the structure as well as blocking.

Now for the column attachment. I know doing moment frames with wood is taboo, and I don't want to do that. The owner is going to let me know if the columns are embedded or just sitting on a cap (as well as size). If on a cap, I suppose I could get away with placing a diagonal at each column up to the beam with either lag bolts or through bolts and call it a day as the lateral load should be pretty minimal.

Any other thoughts?

D

 

[dhoward26]

Second Picture...didn't upload.

 

[dhoward26]

Forgot to mention that blocking is an absolute must as well.

 

[Michel60]

Good morning D,

Good lord, I hope they got a screaming deal on that lumber. Knee bracing should work or you could try tying everything back to the house. I've always operated under the principle if it "looks like a wing it will try to fly", so I wouldn't be bashful about the value for what sort of lift those panels might generate. I think the Structural Engineers Association of California just published some guidelines for the design of roof top photo-arrays. I haven't seen them yet but they may be worth a look.

regards,
Michel

 

[spats]

For wind loading, check out the attached.

 

[spats]

Here's another...

 

[msquared48]

My, but aren't those rafters straight! And is that a specially ordered camouflage beam supporting them?

As there is no diaphragm, among other things. just tie the beam back to the house, and the outside end joist to the beam and house. I would add diagonal strapping and blocking too.

Mike McCann
MMC Engineering

http://mmcengineering.tripod.com

 

[hokie66]

What's supporting those joists back at the house? Looks like they just stop at the metal gutter.

 

[dhoward26]

Thank you for all of the suggestions.

I have been looking at tie'ing beam into the house but I don't want to mess up there soffit too much. The beams and columns are covered in stucco to match the house. They just haven't painted them yet.

As for the connection to the house...that's changing. I attached a picture. Its a beam hung from the truss overhangs as near as I can tell, and then it is lag bolted to something...I assumed the trusses but the owner said the lag bolts were at 32" o.c. He did say he wasn't opposed to adding columns to support it.

Which brings up another issue. They coped the already crooked 2x6 rafters at the end so I have about 3" or so for shear. Haven't run the numbers yet but I don't think it will be too much of an issue.