What it is, how it works, and the questions to ask before you hire.
Last updated: October 2026
Metal siding comes in two generations: the aluminum panels installed on millions of mid-century homes, and modern steel siding — heavier, harder, and finished with durable coatings. Both shrug off insects and rot, and both age in their own ways: aluminum chalks, fades, and dents; steel's risk is coating failure and rust at scratches and cut edges. This guide covers how metal siding performs and what its repair and replacement decisions look like.
Individual dented panels can sometimes be replaced, but matching decades-old profiles and chalked, faded finishes is the hard part — new panels stand out. Small dents are usually left as cosmetic. When dents are widespread after hail, the conversation often shifts to full replacement or siding over, and the condition of what is underneath becomes the deciding factor.
Modern steel siding is galvanized and factory-coated, and holds up well while the coating is intact. Rust starts where the coating is breached — scratches, cut edges, fastener points — so those are the inspection points. Surface rust spots can be treated and touched up; perforation means panel replacement.
Aluminum can be painted successfully — it needs thorough washing to remove chalk, a bonding primer, and quality exterior paint; done right, it refreshes the home for years. Replacement makes more sense when panels are dented or damaged across walls, or when you want to address what is underneath. A sound-but-faded wall is a paint candidate; a damaged wall is not.