DIY Install in Florida. Need help with Engineering diagrams for Permitting

[hbrand]

TundraLu
I want to install a 4kw system on my roof in Edgewater, FL. Could you please post pictures or pdf from your dealings with the permitting? This would help me to modify my system and try to get the permit.
Greetings, Harold

[J.P.M.]

That's absolutely true, I just wanted to emphasize the uplift loads because they can be huge, and people seem to ignore them, thinking only of the weight of the system. For example, my average 16-panel system's added weight was only about 30 pounds per attach point, but the per-attach point calculated uplift using was 300 pounds. I was surprised by that.

Well, it might be true, but at this point it's just my opinion and my point as well, with the additional caveat that there are lots of other things that are also necessary design considerations that most DIYers are unaware of from bolt size and thread pitch to embedment limits in wood, to developed seismic (and yes) wind shear stress considerations, and many other things usually but not necessarily always covered by code conformance.

[sdold]

Ya gotta check everything.

That's absolutely true, I just wanted to emphasize the uplift loads because they can be huge, and people seem to ignore them, thinking only of the weight of the system. For example, my average 16-panel system's added weight was only about 30 pounds per attach point, but the per-attach point calculated uplift using was 300 pounds. I was surprised by that.

[J.P.M.]

The thing you need to be sure of is whether or not the attachments can withstand the uplift forces.

As well as all other additionally imposed forces and moments besides and including uplift from any additions to a structure such as PV equipment, in the limit, from the ground up, as well as the anchorage to the ground.

Example: Not usual or perhaps likely, and maybe/probably a bit absurd, but only to show as an example - adequate or even way overdesigned fixation to a flimsy structure won't do much good if the structure collapses or blows away in a wind event.

Ya gotta check everything.

[sdold]

...i will feel safer knowing i have added bracing for the added weight.

The thing you need to be sure of is whether or not the attachments can withstand the uplift forces.

[J.P.M.]

Ok Got the email to pick up my permit. Yes i will get in the attic and definitely add bracing to each rafter since i will feel safer knowing i have added bracing for the added weight.

One more time: it's about conformance to any required building codes and proper (safe) design to meet possible imposed loads, not simply throwing wood at structural members.

The added weight is probably peanuts compared to the forces and moments added by the compressive, uplift and some shear forces imposed by the wind, or other external forces. Maybe your locality has no codes, or they re not as strenuous as some places, but either way, the forces will be present and ought to be understood and dealt with in the design.

[TundraLu]

You're most welcome. NOMB, but if you have building codes that, among other things, follow ASCE requirements for wind and other external loadings, it'll be more than an idea.

Ok Got the email to pick up my permit. Yes i will get in the attic and definitely add bracing to each rafter since i will feel safer knowing i have added bracing for the added weight.

[J.P.M.]

My friend that is a GSC is coming over to look inside my attic to see if i can brace the roof better if needed. Thanks for the idea.

You're most welcome. NOMB, but if you have building codes that, among other things, follow ASCE requirements for wind and other external loadings, it'll be more than an idea.

[TundraLu]

Just make sure the roof is strong enough to handle the uplift and the bolting to the roof won't be torn out in a wind event. Uplift (and compression by wind forces for that matter) is a lot different and treated differently than dead weight alone.

My friend that is a GSC is coming over to look inside my attic to see if i can brace the roof better if needed. Thanks for the idea.

[TundraLu]

What part of FL are you in? I'm in the Tampa area.

I am in Land O lakes by the new Premium Outlet mall.

[TundraLu]

I used the IronRidge racking setup for my 24-panel ground mount and was very impressed with how solid everything is. You are right that it's not cheap, and the poles were a huge pain to set, but I don't worry about it now.

Roof mount will probably be a lot easier, and somewhat cheaper. (Getting eight 2" holes dug 4 feet deep involved rental costs and paying a buddy to do his Bobcat magic, and the concrete was pricey, too.)

Yes this weather is good. I just didn't want to encroach to close to the Holidays . I see the permit isin the final review phase. Man the prices here for a permit is not cheap. So far it looks like 500.00. Hopefully it gets approved by Monday.

[J.P.M.]

I used the IronRidge racking setup for my 24-panel ground mount and was very impressed with how solid everything is. You are right that it's not cheap, and the poles were a huge pain to set, but I don't worry about it now.

Roof mount will probably be a lot easier, and somewhat cheaper. (Getting eight 2" holes dug 4 feet deep involved rental costs and paying a buddy to do his Bobcat magic, and the concrete was pricey, too.)

Just make sure the roof is strong enough to handle the uplift and the bolting to the roof won't be torn out in a wind event. Uplift (and compression by wind forces for that matter) is a lot different and treated differently than dead weight alone.

[BackwoodsEE]

I used the IronRidge racking setup for my 24-panel ground mount and was very impressed with how solid everything is. You are right that it's not cheap, and the poles were a huge pain to set, but I don't worry about it now.

Roof mount will probably be a lot easier, and somewhat cheaper. (Getting eight 2" holes dug 4 feet deep involved rental costs and paying a buddy to do his Bobcat magic, and the concrete was pricey, too.)

[Matrix]

Everything arrived perfectly. Went up on the roof and mounted a Guardian Fall Protection Anchor on the ridge to work safely as my house is 2 story. Man that thing works awesome. I can now walk anywhere on the roof with confidence. Before i was crawling around hahaha.

Awesome. Sounds like you are well on your way. Good time of year in FL to do an install. Oddly, the 1st few weeks in Oct in FL was so hot this year when I did mine I nearly expired.

[CessnaTPA]

Everything arrived perfectly. Went up on the roof and mounted a Guardian Fall Protection Anchor on the ridge to work safely as my house is 2 story. Man that thing works awesome. I can now walk anywhere on the roof with confidence. Before i was crawling around hahaha.

What part of FL are you in? I'm in the Tampa area.