You will need to build this like you would any other space. Having the slab doesn’t help you. It hurts you. It’s in the way of creating a foundation and running the electrical that will be needed. Breaking it up and doing it correctly as a projex t with a monolithic foundation and slab pour is your best bet. Contact a local licensed and insured contractor to do just that for you.

Can you buy a pre-fab one? I have never seen/used before, but just googled it and it looks like they exist...

https://www.ecanopy.com/pascenwhgrco.html?Choose%20Size=79322%20-%207ft%208in%20X%2011ft%206in&gclid=CjwKCAjwxrzoBRBBEiwAbtX1n2FAtVLLNJOmkfFalhT3ViMcUAUXUOmIlkaMJURTVJn2Qyy_fki94hoCLTAQAvD_BwE&refnum=Jun-157-0886

Prefab doesn’t help. It doesn’t save any money to do something so questionable in quality. You need a foundation and the proper infrastructure.

I have no idea the feasibility of this or not in your locale, but, if you secure the structure to the house and to a new perimeter foundation, which you’ve placed on the outside of the patio slab on the remaining three sides, that might be worth checking out. (So basically the existing patio is simply floating in the middle as if it were just lawn.)

Anyway, it’s a starting point. Here’s kind of what I’m talking about, footer depth and connectors, etc. notwithstanding:

How to build a screened-in patio

When we built a screened in porch in St Louis decades ago, the slab had to have 2 ft deep footers.

Florida = Hurricane Impact in most of the state. Where are you OP?

South Central Florida. South of Kennedy Space Center, but not on the coast itself. I'm aware that I need to meet hurricane regulations and the related codes. There are lots of porches that look like aluminum frame with inlaid screen in my area; I just don't know how to go about installing it.

The slab is well over 3" thick. I'm not worried about that. No electrical goes through the ground here; everything it through the walls and attic areas.

"The slab is well over 3" thick. I'm not worried about that."

But what has the building dept, or engineer said about the slab? How do plan to tie this into the existing house while maintaining hurrican requirements on both the screen porch and the house?

I think you missed my initial questions at the top. I said I need help starting, which means that I don't have a plan yet; I'm trying to develop one. This is our first project for the house besides minor interior changes; I don't know where the right place to start even IS. If you're saying to start with my city building department then that's helpful, but I'm not sure what you mean. I don't know anyone that has hired an engineer for house building. Architects, yes, but why do I need an engineer?

Sammy, I appreciate the schematic. I'd be interested in seeing if that would be a good alternative if it would be infeasible to use the slab directly. If it needs footers like Anglophilia did, but it wasn't installed with them, then it may be the best option.

Maybe I need to rephrase for those that keep asking about my plans: Has anybody had a screen porch built over a slab (not deck), whether they did it themselves or hired a contractor? What is a good starting point? My plan is that I want a screen porch, and I have a slab. Do I start with the city building department before looking at anything else, or talk to contractors? What kinds of questions should I be ready to ask or answer?

You are not going to be able to recreate your neigbor’s ramshackle things that are grandfathered in, and that will get blown away. You should start with a licensed and insured contractor who will talk to you about demolishing the slab to be able to correctly create what you want, with permits and inspections from the building department. 40K+ as a very very basic start, to do this correctly, to hurricane building requirements.

There is no other way to do this and not get dinged by fines or denied coverage by your insurance. If a contractor doesn’t furnish you with copies of his license and insurance, or want to do the job with permits and inspections, then move on to the next one. Most good contractors are going to be 4-6 months out right now. And they will cost way more than you will anticipate.

Call companies that install pool screen enclosures.

Yes you need to talk to the city to find out exactly what is required then if you can go ahead get quotes from contractors and IMO you are not in a position to DIY this since you are asking all these questions .Armstrong Aluminum is in Orlando maybe start there if you are looking for prefab.

Call companies that install pool screen enclosures.

A pool screen enclosure is not a permanent structure.