Can You Paint Aluminum Siding?
By Dunwoody Painters ·
Yes, aluminum siding can be painted when the panels are firmly attached and the problem is a faded, chalky factory finish. We soft wash the chalk off, scrape failing paint to a sound edge, caulk every joint, prime bare or chalky spots with a bonding primer, then apply two finish coats. A professional repaint lasts 8 to 10 years on aluminum.
Why does aluminum siding chalk, and why does that matter for paint?
Chalking is a fine, white powder that forms on the surface of an exterior paint film as it weathers, and it is what makes an older finish look faded [1]. Sherwin-Williams lists factory-finished siding among the causes: that finish can build up an excessively thick chalk layer that may need power washing to come off completely [1].
The chalk has to go before any paint does. Aluminum siding is normally painted only after it has faded and chalked, and if the chalkiness is not removed, the paint will not adhere properly [2]. Benjamin Moore’s data sheet for an exterior paint it recommends for aluminum siding also calls for removing excessive chalk first [6].
To check your own siding, rub it with a dark cloth. A powdery residue means sun has broken down the binder and the coating is spent. Start on the south and west walls, which take the most sun and chalk first.
Which aluminum siding should be painted, and which replaced?
Paint renews the finish, not the shape of a panel or how it hangs. Walk each side of the house and sort what you see into these rows.
| What the siding looks like | The call |
|---|---|
| Faded or chalky, but firmly attached | Paint. Wash the chalk off first so the new coat can adhere [2]. |
| Peeling paint from an earlier repaint | Paint, once the loose paint is scraped back to a sound edge. |
| Bare metal showing through the finish | Paint, after a bonding primer on those spots. Primers are usually needed only on a bare substrate [5][6]. |
| Loose or pulling away from the wall | Fasten or replace those pieces first. Paint will not hold a loose panel in place. |
| Dented, creased or bent | Paint will not change the shape, so the dent stays visible. Sherwin-Williams ties a factory-finished look to siding that is not bent or damaged [4]. |
On the peeling row, Sherwin-Williams suggests finding out why the old paint peeled so the cause can be corrected before the repaint [5]. On mid-century ranches in Doraville and Embry Hills, aluminum often shares the wall with old wood trim, and rotted trim and fascia are cut out and replaced before the painters start. If part of the house is vinyl, those panels follow their own rules, covered in our guide to painting vinyl siding.
How is aluminum siding prepped and painted?
An aluminum repaint runs in the same order as our siding painting and repair service, with the primer step matched to bare metal:
- Wash. We soft wash away chalk, pollen and mildew. Sherwin-Williams’ guidance for aluminum is a wash with the correct detergent to remove chalk, oil and other foreign material [4]. The wash is our power washing service, folded into the same estimate.
- Dry. The siding dries fully before any coat goes on. Sherwin-Williams suggests a day or so after washing, so water driven up behind the panels can work its way out [3].
- Scrape. Failing paint from an earlier repaint is scraped back to a sound edge.
- Caulk. Every joint is caulked. Sherwin-Williams suggests replacing old, cracked caulk with new acrylic latex caulk [5].
- Prime. A bonding primer goes on bare or chalky spots. Sherwin-Williams says aluminum siding rarely needs to be primed unless it has a super-slick surface [4], and Benjamin Moore’s repaint instruction is to prime the bare areas [6].
- Finish. Two finish coats. Sherwin-Williams recommends a high-quality acrylic coating for the best resistance to chalking [1].
How long does paint last on aluminum siding?
A professional repaint lasts 8 to 10 years on aluminum, the same range as vinyl, against 10 to 15 years on fiber cement and 5 to 8 years on wood. Expect the low end on the south and west walls, which take the most sun. Our guide to how long exterior paint lasts breaks the numbers down by surface.
Two habits push a repaint toward the long end: washing the siding once a year, and re-caulking every two to three years. Open seams at butt joints, corner boards and windows let water straight in, and waiting too long turns a paint job into a carpentry job.
When should you have the siding assessed?
Book a walk-through if you see any of these:
- Chalk on a dark cloth, or one wall noticeably lighter than the rest.
- Paint from an earlier repaint peeling off the metal.
- Panels that are loose, dented or pulling away from the wall.
- Trim or fascia that gives when you press a screwdriver into it, which is rot that needs new boards before paint.
We walk the siding with you, measure, note problem areas and confirm the finish you want. You then get a written line-item proposal with the products, prep scope and schedule. Every project carries our written 2-year workmanship warranty, and you pay nothing until the job is finished. More exterior questions are answered in our painting guides.
Book a free siding assessment and we will tell you whether your aluminum siding is ready for paint.
Sources
- “How to Fix Paint Chalking,” Sherwin-Williams. https://www.sherwin-williams.com/en-us/project-center/maintenance-repair/paint-chalking
- “Exterior: Product Application Frequently Asked Questions,” Sherwin-Williams. https://www.sherwin-williams.com/home-builders/color/resources/faqs/exterior-product-application-faqs
- “Exterior: Surface Preparation Frequently Asked Questions,” Sherwin-Williams. https://www.sherwin-williams.com/painting-contractors/products/resources/resources-faqs/exterior-surface-preparation-faqs
- “Know Your Substrates & What to Use on Them,” Sherwin-Williams. https://www.sherwin-williams.com/home-builders/products/resources/pro-tips/sw-article-pro-knowyrsubstrate
- “Exterior: Product Selection Frequently Asked Questions,” Sherwin-Williams. https://www.sherwin-williams.com/property-facility-managers/products/resources/faqs/exterior-product-selection-faqs
- “Regal Select Exterior Paint, MoorLife Flat Finish (W105) Technical Data Sheet,” Benjamin Moore. https://media.benjaminmoore.com/WebServices/prod/assets/stage/datasheets/TDS_0105/20200421%20W105%20TDS%20US%20OKF.pdf
Not across the whole house, in most cases. Sherwin-Williams says aluminum siding that has weathered a year does not need primer, as long as it is cleaned free of chalk and residue first. We still apply a bonding primer to any spots that are bare metal or chalky, before the two finish coats.
A high-quality exterior acrylic, not an oil-based paint. Sherwin-Williams says alkyd (oil-based) paints are usually not recommended directly on aluminum, because the alkyd can react with the aluminum when moisture is present. Its aluminum siding guidance names exterior acrylics for a long-lasting finish over a properly prepared surface.
Wash it with a detergent, rinse well with clear water, and wash again if chalk still comes off; scrubbing may be needed. Dark spots left after the wash may be mildew, and Sherwin-Williams suggests testing them with a few drops of household bleach, since mildew bleaches away. Let the siding dry fully before any coat goes on.
Paint it when the panels are firmly attached and the trouble is fading or chalk, which a wash, spot priming and two finish coats take care of. Refasten or replace loose panels first. Paint will not change the shape of a dented or creased panel, so replacing those pieces is the way to remove the dents.