Roof layout and mount questions - and fire access

[d_1d]

Hello, all. Questions about racking/mounting for a peculiar roof.

I'm considering options for my small hip and valley roof. If I read the regulations correctly, a large portion of my south-facing roof will be taken up by fire access -- namely the 3 ft from ridge and 3 ft ladder access for any roof surface.

One proposed arrangement for 11 panels is attached. However, I am unsure if/how I can put racking up for the landscape array. Notice the middle row is shifted over. If those are put in portrait orientation, they are just barely into the 3' zone at the top.

What are your suggestions in this situation? Can rails be installed like that, and how would the panels be clamped to them? Thanks a ton!

[ButchDeal]

Hello, all. Questions about racking/mounting for a peculiar roof.

I'm considering options for my small hip and valley roof. If I read the regulations correctly, a large portion of my south-facing roof will be taken up by fire access -- namely the 3 ft from ridge and 3 ft ladder access for any roof surface.

One proposed arrangement for 11 panels is attached. However, I am unsure if/how I can put racking up for the landscape array. Notice the middle row is shifted over. If those are put in portrait orientation, they are just barely into the 3' zone at the top.

What are your suggestions in this situation? Can rails be installed like that, and how would the panels be clamped to them? Thanks a ton!

most modules now allow landscape with east west rails.

[tehan]

I would at least look at putting the panels on your West facing roof. It will be a much simpler install and with the money you save on rails and labor you can probably add an extra panel or two so the production will stay about the same.

[d_1d]

Good suggestions, to both of you. Thanks.

I'll definitely look at the west-face now, but it's slightly west-northwest.
From the panel install guides, it sure seems they all want them clamped near the "holes" +-3", on the long-sides. Maybe that's old material, and people do it anyway now?

[d_1d]

Any thoughts on QuickRack, rail-free mounting? From what I can see, it may be a good option in this situation.

[foo1bar]

Good suggestions, to both of you. Thanks.

I'll definitely look at the west-face now, but it's slightly west-northwest.
From the panel install guides, it sure seems they all want them clamped near the "holes" +-3", on the long-sides. Maybe that's old material, and people do it anyway now?

Each panel/manuf. has their own installation requirements.
Mine were LG 280s and they allowed/required within 120mm of each edge if clamping on the short side.
if clamps were on the long sideit was at least 270mm from each edge, but less than 500mm


If it were me, I'd ask the fire dept for a waiver so I could do the full south face.
And so that I could have the panels out to the East edge on the farther back slope - so they woudln't get shade from the roof to the west.
My guess is if you ask nicely they'll be OK with it - they'll still have plenty of room to get up on the roof and cut holes as needed.

[tehan]

Landscape is possible but should never be your first choice. And splitting your array in two like that is going to require a long conduit run and/or additional roof penetrations. It looks like the East (and slightly South) facing roof can take two rows of portrait. I would at least look at the production on that using PVWatts vs the South roof. One thing that might help is to count the number of roof penetrations your design will require. My guess is your current design will need about 36 roof penetrations vs about 20 for a simple two-row portrait layout. I suspect QuickRack will require even more.

[Naptown]

What specifically is the code that is requiring the setbacks?
On a hip roof you can go all the way to a hip if no panels are on the other face
Same with a valley
If both sides of a hip or valley have panels then you have to stay 18" from each side
If the IRC2015 is the code see the errata from the International Code Conference where they deleted this requirement from the code

[solarix]

Since you have a hip roof, you can count the adjoining roof as the access path and only have to leave 3ft clearance on the peak.
I would still avoid the landscape layout if at all possible. If the front roof is EastSouthEast, use it too.

[inetdog]

Since you have a hip roof, you can count the adjoining roof as the access path and only have to leave 3ft clearance on the peak.
I would still avoid the landscape layout if at all possible. If the front roof is EastSouthEast, use it too.

In the code currently enforced in CA there is no express exception for a ridge line which is clear on only one side.
But the code allows waivers/exemptions by the local Fire Marshall and those are generally granted for this particular situation.

[d_1d]

In the code currently enforced in CA there is no express exception for a ridge line which is clear on only one side.
But the code allows waivers/exemptions by the local Fire Marshall and those are generally granted for this particular situation.

Ahh, well, I am in San Diego.
I did read the errata referenced above, and it does seem to relax that requirement. Plus, I found L.A. permitting docs that show it is now allowed (I think). So, I'm hopeful.

I may just push forward with the plans assuming I will be granted a waiver.
Would this be done as part of the normal permitting process? How do I get a waiver from the Fire Marshall? They are probably too busy to deal with little-me!
I will probably cite the code errata in the plans as a note, and hope the reviewer/inspector understands.

With this requirement lifted, I can do all 12 panels on the south-southwest facing slopes to take advantage of NEM TOU times (I'll be on SDG&E time-of-use--electric vehicle times). Everything will be portrait, except one row of 3 landscape panels, which is a pretty fair trade.

Thanks very much, you guys/gals.

[foo1bar]

How do I get a waiver from the Fire Marshall? They are probably too busy to deal with little-me!

In my case I asked at the planning office. They told me which office I needed to talk to for getting the waiver. Then I walked across the courtyard, and setup an appointment for a few days later to meet with the appropriate person.
I wouldn't expect them to be too busy to deal with you - their job is to deal with these things.
(And if you hire someone to do the install for you, IMO their job is to meet with the fire dept for you. )