Rust Stains on Pool Cage Screws and Anchors

The aluminum frame itself does not rust — aluminum corrodes and oxidizes, which shows up as a chalky white or gray residue, not orange streaking. Orange rust bleed running down from a screw head or an anchor point is a different metal entirely: the self-tapping steel screws holding the spline channel to the frame, doing exactly what steel does in Florida humidity over decades.

This is the fact that shapes every rescreen quote on an older Casselberry cage. The median house here was built in 1980, and self-tapping screws that have spent four decades in aluminum do one of three things when a screwdriver goes near them: back out clean, spin in a stripped hole, or shear off flush with the frame. Visible rust bleed is a preview of which of those three you are likely to get — a screw already staining the frame around it has already lost most of its grip.

What to look at before assuming it's just cosmetic

• Whether the stain is isolated to a few fasteners or runs the length of a wall — spread staining usually means the whole run of screws is on the same clock
• Whether the screw head still shows a clean drive slot, or is already rounding out
• Whether staining tracks with sun exposure — the elevation taking the most direct sun usually shows both chalking and rust bleed first

Isolated staining on a couple of fasteners is a repair-while-there item. Staining across a wall or the whole cage is a reason to ask for a full-rescreen quote with fastener replacement priced as its own line rather than an afterthought — see frame and upright repair cost if the corrosion has gone past the fastener into the frame member itself.