Rail-less Unirac mounting system with bottom row on the eaves of roof

[BlueMarblePA]

I bought a used system which included the racking material -- Unirac SFM Infinity microrails/rail-less sytem. I can re-use this in my 7.6kW roof, but I want to be able to overpanel and ultimately add extra panels at the ridge. However, in order to do this, I really need to start my panels as close to the eaves as possible.

With a conventional rail system, I could put in the L-feet away from the eaves/gutter, but with the rail-less system, I need to start my row at the bottom of the panels which puts me very close to the eave/gutter. Is there any kind of structural concern with doing this? Basically, if the weight of the panels is placed on the eaves, is there a cantilever engineering concern?

 

[ncsolarelectric]

I don't think the structural attachment is a concern, but the fire code may require them to be away from the eves for walkways.
I've used the SFM Infinity racking. It's cheap, but it's not fast, or easy unless you're a 1-man installer and have the process down pat. The components need to be precisely where they are shown on the plans, and crews don't always follow the plan. That causes shortages and rework if the inspector doesn't like what they did. I prefer ground mounts!

 

[BlueMarblePA]

I don't think the structural attachment is a concern, but the fire code may require them to be away from the eves for walkways.
I've used the SFM Infinity racking. It's cheap, but it's not fast, or easy unless you're a 1-man installer and have the process down pat. The components need to be precisely where they are shown on the plans, and crews don't always follow the plan. That causes shortages and rework if the inspector doesn't like what they did. I prefer ground mounts!

Can you elaborate on the difficulty of installation? I am a one man installer as it is my own roof for my own house. Fortunately it is a ranch house and I am planning to get some scaffolding so I can stand on it and work near the eaves for the first important row.

 

[Solar Guppy]

NFPA 2018 and newer requires set backs from all 4 side on the roof, typically 3ft minimums and depending on the length of the array, walk ways between a row. ( This is from the National Fire Protection Association )

While physically you can add things to your roof, most city's and towns have building departments and permits would be required to install any thing attached to a roof ( even just re-shingling ). For sure you can't just go edge on any of the faces of the roof, well you can but with gridtie it you going to have to have a permit, so code do matter.

 

[ncsolarelectric]

Can you elaborate on the difficulty of installation? I am a one man installer as it is my own roof for my own house. Fortunately it is a ranch house and I am planning to get some scaffolding so I can stand on it and work near the eaves for the first important row.

First, create yourself an account at Unirac.com, Designer platform, and create a new layout for the panels on your roof for the SFM Infinity. It will provide you with a plan of where all the pieces go, with engineering details to go with it. Compare that to what you have. I'm afraid that the parts that fit someone else's roof, won't fit the same on your roof if you change the layout, or for many other reasons. IMO, it's best to start with a fresh design, and then match up the parts to get it right.
The difficulty with SFM Infinity, IMO, is that everything must be measured to precision, and put in the right place. Comparatively, using rails is easy because there's lots of leeway to add an extra attachment or splice a rail if needed. SFM infinity doesn't have that flexibility. It's like a jigsaw puzzle.

 

[x98myers7]

it's quite a bit less complicated than people think. you can absolutely place panels to the edge of the roof provided you follow access guidelines and you can secure them as required. i would be more concerned with securing them correctly than setback. this is the best setback guide on the internet --

6.20.18 Firecode and Smarter Inverters

Shared with Dropbox

www.dropbox.com

 

[BlueMarblePA]

it's quite a bit less complicated than people think. you can absolutely place panels to the edge of the roof provided you follow access guidelines and you can secure them as required. i would be more concerned with securing them correctly than setback. this is the best setback guide on the internet --

6.20.18 Firecode and Smarter Inverters

Shared with Dropbox

www.dropbox.com

Thanks for this. Rails allow me to bring the panels all the way down to the eaves, but the Rail-less system does not allow that as the initial rail needs to be set at the bottom of the modules where there is tenuous support on the eaves. I will review this more carefully.