Top Tips for Painting Aluminum Siding

Chances are, if your home was built during the 1940-1970s, you’re likely to have been graced with aluminum siding.  After an increase in manufacturing capabilities, aluminum became a cheaper and relatively hassle-free alternative to the previously common wooden clapboard siding.  The metal was chosen for its ease of application, durability, and long-lasting finish.  After exposure to air, aluminum undergoes a chemical reaction and converts to aluminium oxide, forming an extremely hard coating that adds a layer of protection to your home.  This, combined with the layer of baked on enamel that gives the siding its color, made for a material that is only just beginning to need serious maintenance several decades later.  Luckily, the maintenance is more cosmetic than anything, and with proper care and professional expertise, aluminum siding can look brand new again.  All it takes is a fresh coat of paint. 

Prep, Prep, Prep

We know, we consistently sing the praises of proper preparation, but only because it’s so vital to a successful paint job.  In the case of aluminum siding, prep is still as important as ever.  As the siding ages and is exposed to the elements, the enamel-based coating that once prevented issues will degrade due to oxidation and turn into an unsightly chalky powder.  To remove this powder, use an abrasive sponge soaked in either a homemade mixture (consisting of chlorine bleach, water, and trisodium phosphate) or a commercial cleaner purchased from a hardware store.  Either choice will also kill any mildew that may be growing on the surface of your home and remove other potentially damaging materials.  After a thorough washing, be sure to spray your home down with water, and allow it to dry before attempting to paint. 

As professionals, we like to supercharge the cleaning process by adding our cleaning solution to a pressure washer equipped with a fan-spray tip.  This allows for more efficient removal of debris and helps strip away years’ worth of oxidation.  Be warned, however, that the potential for damage when pressure washing is a very real concern.  Our experts are trained to use pressure washers and understand proper usage guidelines, such as always spraying down on the siding, which will prevent damage to your home. 

Choose the Correct Paint/Primer

After prepping, the next step is choosing the correct material to finish the job.  There is a decent amount of debate in this realm, especially surrounding primer.  Some swear by it, while others feel it is unnecessary on aluminum siding.  While we’ve seen jobs turn out fine using both methods, we still recommend using an oil-based primer.  This ensures maximum protection and paint adhesion.  Oil-based must be used because the ammonia in latex primer may react with any remaining oxidation, causing bubbles to form.  For highly oxidized homes, Emulsa Bond, an oil-based additive for latex paint, can help paint bond to the surface despite any remaining chalk. 

Choosing which type of paint to use for your aluminum siding project is more straightforward.  Always opt for 100 percent acrylic paint, and apply two or more coats.  This paint is very durable, and is flexible enough to resist expansion and contraction during temperature changes that may otherwise cause cracking.  If used in conjunction with Emulsa Bond, apply the Emulsa Bond coat as the base coat. 

Pro Tip: Choose a flat or satin finish.  Glossier paint can highlight dents or scratches in the aluminum. 

Hopefully these few tips have given you insight into the specifics of painting aluminum siding, which is often easier and more affordable than switching to vinyl siding.  When properly maintained, your aluminum-sided home can last for decades.  If you have any questions about aluminum siding or any other painting needs, don’t hesitate to contact us.  Boulder is our home, too, and we love caring for the homes in our community.