re: Need Help With A Screen Porch

Need to remove that railing, doesn't look like they did a great job on it anyways. I'd use treated, or cypress/ cedar 2x4 on the bottom anchored to slab. You can run the screen all the way down to that or use plywood to make some panels that come up a few feet.

Either way you would regret having that gap. Also i'd use the plastic screen material. I used the metal the first time thinking it'd be stronger but it shows every kink and bend. The plastic is more forgiving.