Metal fencing holds up to two things that wreck other fences around here: termites and standing water. What it does not shrug off is salt in the air. Anything ferrous within reach of the river and the marsh will find a way to rust eventually, so the real decision on a metal fence in Chalmette isn't metal versus wood — it's which metal, with what coating, and how the bottom of it is going to sit in relation to the ground.
Genuine wrought iron is mostly something you repair rather than something you buy new. If you have it, it's old, it's probably hand-worked, and the right move is usually to cut out the failed sections, fabricate replacements to match the scrollwork, and refinish the whole run so the patch doesn't announce itself. Most "wrought iron" sold today is ornamental steel — tube pickets welded to rails, hot-dip galvanized or zinc-primed, then powder coated. It's strong, it takes impact without bending, and it rusts the moment that coating is breached. Aluminum doesn't rust at all, which is why it's the common choice for pool enclosures, canal-side yards and anywhere the fence line stays damp. The trade-off is that aluminum dents where steel would hold, so for a driveway gate or a fence a dog throws itself at, steel is usually the better spend.
Where metal fences fail is predictable: the cut ends, the welds, the bottom rail, and the first few inches above grade where grass clippings and moisture sit. Ask how the ends are treated after cutting, because a field cut on a galvanized picket exposes bare steel. Ask whether posts are set with the concrete crowned and sloped away so water doesn't pool at the base. On the Gulf Coast those two details decide whether a steel fence looks right in a decade or starts weeping orange streaks in three years.
The ground in St. Bernard Parish is soft, wet and inclined to shift. There's no frost depth to worry about, but there is a high water table, and a post hole will often start filling before the concrete goes in. Posts have to go deeper than you'd expect for the fence height — particularly gate posts and corner posts, which carry all the load. On a long run, line posts can be set more modestly, but gate posts should be oversized, set deep, and ideally tied to a larger footing, because a sagging gate is the single most common complaint on metal fencing and it almost always traces back to the post, not the hinge.
Good installation starts with locating the property line and calling in utility locates before anything is dug. Then string lines, post layout, holes, posts plumbed and braced, concrete, and only then the panels. On sloped or ditched ground — and there's plenty of it between Chalmette and Meraux — panels either rack, meaning the pickets stay vertical while the rails follow the grade, or they step down in level sections. Racking looks cleaner and leaves no gaps underneath; stepping suits a formal look and sharper grade changes. That choice should be made on site with you standing there, not assumed off a drawing.
Linear footage is the starting point, but the variables that move a quote most are height, gauge and whether the fence is aluminum or steel; the number of gates and whether any are double-swing or automated; post spacing and footing size; access for equipment; and whether an old fence has to come out and be hauled off. Corners, slopes and curved runs add posts. A pool fence has its own requirements for height, picket spacing and self-closing, self-latching gates, and getting that wrong means failing inspection and paying twice.
Before you book anyone, ask what the coating system actually is and what happens at field cuts; ask how deep the gate posts go; ask who handles permits or subdivision approval, and whether locates are being called. Ask to see how the bottom rail sits relative to grade. And if you're restoring existing ironwork in Arabi, Gretna or anywhere with older housing stock, ask whether the repair will be welded and ground flush or simply bolted — the difference shows from the sidewalk.