Aluminum siding will protect your home from inclement weather for many years. However, after a period of time, the suns UV rays, rain, hail, windblown dirt and air pollution will all take their toll on the aluminum siding’s paint finish, as shown in Figure 1.
Figure 1 - House with aluminum siding
The disappearance of the high gloss that was usually placed on the aluminum siding is the first thing that will happen, followed by the paint fading and then, eventually the paint will begin to flake.
If the siding is still doing its job – protecting your home from the elements, it is not necessary to replace the aluminum siding. Aluminum siding can be painted, which will make it look like new at a fraction of the cost of replacement.
If you want to paint your aluminum siding, follow these four steps:
The siding must be washed in order to remove all mildew, insects, dirt, grime and flaking. A fresh coat of paint primer will not stick to dirt and grime and will not stop paint that has flaked from coming off the siding.
Wash the siding using a telescoping brush with soap and water. There are numerous environmentally safe and biodegradable siding cleaners available. Make sure you wash all the nooks and crannies and any creases in the siding.
Note: I do not recommend the use of a power washer on siding of any type. Unless you are an expert at controlling the pressure and spray it is very easy to drive water underneath the siding which can create mildew, mold and rot to the sheathing beneath the siding. As well, power washers require that you take extreme care around any electrical boxes and electrical services.
Rinse the soap off the aluminum siding, again make sure you get it all. Continue to rinse until the rinse water is clean and free from any paint chips or flakes.
Always start at the highest point and work your way down. This prevents dirt and other contaminants from ending up on areas of siding that have already been washed.
This is a very important part of the painting process. Take the time to ensure that all contaminants have been washed off the siding.
Allow the siding to completely dry before proceeding to step 3. This may take a few days depending on the climate.
Note: You will find many books and articles on the internet, that suggest the use of a latex based primer. Latex based primers, because they contain amonia will react with any oxidized aluminum and this will lead to blistering of your new paint job.
DO NOT USE A LATEX BASE PRIMER!
Additional information about paint primers.
Apply the primer using a brush, roller or pad. The application tools that you use will depend on your personal preferences and the texture on the siding, if any.
The primer can also be applied using a paint sprayer. However, caution should be taken as spraying exterior surfaces can lead to paint splatter in places that you were not planning on painting, such as driveways, outdoor furniture, and fences! If you do use a paint sprayer, adjust the thinning of the primer accordingly.
Use a 100% acrylic exterior paint for the finished coat. Yes, a 100% acrylic exterior paint will not be the least expensive exterior paint on the store shelf. But if you don’t want to have to paint your aluminum siding every other year, buy a very high quality paint!
The finished coat must be applied within 48 hours of applying the primer. If you wait longer than that you could have problems with the finished coat of paint bonding to the primer.
Note: The best time to paint is on a cloudy, cool day with no wind. Do not paint if it is hot out or if it is windy. The finished coat of paint needs to dry slowly in order to bond properly to the aluminum siding and then the primer.