Painting Metal Siding

As a painting company, we are often asked whether there is a right way to change the color of existing metal siding. There is. Metal siding can be repainted successfully, but the result depends far more on inspection, cleaning and coating choices than on the color itself. This guide walks through when repainting makes sense, how to prepare the surface, and what to consider before choosing a color and finish.

Can Metal Siding Be Painted?

Yes. Vinyl may be the more common siding material today, but metal siding remains on many homes, and aluminum siding in particular has been used on houses for decades. Newer options such as zinc and copper exist, but aluminum and steel are still the metals most homeowners encounter on residential exteriors.

Part of metal siding's appeal is that it does not try to imitate wood, stone or brick — it has its own clean look — and it is generally durable and low maintenance. It does have weaknesses: it can dent and scratch, and over time the factory finish or a previous paint job will wear. Because metal is non-porous, it can be repainted to look fresh again, provided the surface is prepared correctly and the coatings are suited to it.

Aluminum vs. Steel Siding

It helps to know which metal you have. Aluminum is lighter and softer, so it dents more easily, and as its finish ages it tends to chalk and oxidize rather than rust. Steel is heavier and more dent-resistant, but because it is a ferrous metal it can rust where the protective coating has been scratched, chipped or worn through. That difference affects how the siding is cleaned, how exposed areas are treated and which primer is appropriate.

Signs It May Be Time to Repaint

Even pre-finished metal siding eventually shows wear, especially on older homes. Watch for:

• Chalking — a powdery residue that comes off on your hand when you touch the siding
• Peeling, cracking or chipping of the previous paint or coating
• Rust spots or streaks on steel siding
• Cracked or failed caulk at trim, corners and openings
• Loss of gloss
• Fading or thinning of color, often most visible on the sunniest walls

It is usually better to address these signs early. Small areas of coating failure are easier to correct than widespread peeling or rust, and a refreshed exterior also matters if you are preparing a home for sale.

Inspect and Repair Damage First

Correcting existing damage is part of surface preparation. Because metal siding dents, check every elevation closely. A badly dented panel is usually better replaced than painted — paint will not disguise a deep dent, and fresh color can make it more noticeable.

While you are inspecting the siding, look at the surrounding components as well: loose or displaced panels, sagging gutters, damaged soffits and downspouts. If the house is being repainted, it is the right time to fix the things around the siding too, so the new finish is not compromised by water or movement from an unresolved problem.

Cleaning and Surface Preparation

Paint needs a clean surface to bond. Before painting, the siding should be free of dirt, grease, bird droppings, mildew, mold, loose chalk, old failed caulk and other debris.

Washing is typically part of the process, but the method and pressure have to suit the siding and its condition. Aluminum can bend and dent under too much pressure, and a stream aimed upward or at seams can drive water behind the panels. When washing, direct water downward — the way rain hits the house — and keep pressure moderate. Depending on how dirty or chalky the surface is, warm water alone may be enough in some cases, while heavier chalk, mildew or grime may call for a cleaner suited to the substrate and the coating that will follow. Rinse thoroughly and let the siding dry completely.

Homeowners can wash their own siding, but very dirty, heavily chalked or tall exteriors are often worth handing to a contractor who can match the cleaning approach to the surface.

Check Whether Your Siding Needs Primer

Priming is generally needed when:

• Bare or exposed metal is showing
• The surface is severely weathered
• The siding still feels chalky after thorough cleaning
• Rust has been treated on steel siding

Where primer is needed, peeling and cracked paint should be scraped and sanded so the edges are sound before priming. Rust on steel siding should be removed down to a stable surface and treated with a primer intended for ferrous metal.

Choosing a Paint Color

Decide on the color before painting, and test it on the house rather than relying on a chip. Darker colors absorb more heat from the sun, which can increase surface temperatures and expansion. Some siding and paint manufacturers limit how dark a color can be used on their products, especially on factory-finished metal, so check those limitations before committing to a deep shade. Fading, chalking and other discoloration can also be more noticeable on darker colors.

Get samples and apply them to a small section of siding, then look at them at different times of day. For more help with palette decisions, see our exterior paint color combinations and guide to exterior house colors by home style.

Choosing a Sheen

Finish affects appearance and upkeep. Flat or matte finishes can look contemporary and help hide minor surface imperfections, but they are harder to clean and tend to hold dirt. Satin and similar low-luster finishes are easier to wash and generally resist staining better.

That said, sheen is a secondary decision. A well-chosen satin over poorly cleaned, chalky or incompatible surfaces will still fail. Surface condition, primer selection and coating compatibility have a much greater effect on how the job performs than simply choosing flat versus satin.

Professional vs. DIY

Painting metal siding can be a DIY project, especially on a small, single-story home with siding in good condition. On larger homes, or where there is widespread chalking, rust, peeling or damaged panels, a professional painting contractor can help with the decisions that most affect the result: which panels to repair or replace, how to clean without damaging the siding, where primer is required and which products are compatible. Working at height on an entire exterior is also a significant safety consideration.

If you are in the Kansas City area and considering repainting your siding, our exterior painting team can evaluate its condition and recommend a scope.