Stucco siding provides a high-quality finish to the side of your home, and provides superior durability and sound insulation when compared to other types of siding materials. However, like all materials that are exposed to the weather, stucco siding can become marred by mold and mold stains over time. Fortunately, you can easily clean your siding and get the stucco back to looking brand new with the right tools and materials.
What You'll Need
Gather everything that you'll be using during the cleaning process so that it goes as quickly and smoothly as possible. You'll need a sponge or a pump sprayer, a pressure washer or a high pressure attachment for a garden hose, borax, liquid cleaning detergent, a soft bristled brush, a set of safety goggles, gloves, a mask, and a large bucket. All of these items can be found at most hardware stores if you don't already own them.
Removing Mold Stains from Stucco
First, you should rinse down the area of your siding that has become stained with mold. This will help remove any loose mold and dirt which may be stuck to the stucco and will allow for the mold killing chemicals to gain a better degree of saturation when they are applied.
Then, you'll want to make a mold killing solution. Combine a gallon of hot water with a cup of borax and a half cup of liquid detergent: mix it a little bit to combine all of the ingredients. This is a potent mixture that should be able to eliminate most mold stains and restore the appearance of your siding.
For small areas that are affected by mold, you can use a sponge to apply the mixture, scrubbing lightly and in a circular motion to work the solution into the mold. For larger areas, where applying the solution by hand would be cumbersome, you can pour the solution into a pump sprayer and then apply it to your siding. Just be sure to cover any nearby plants and spray only a small distance from the wall, as the solution can be toxic to other organisms in your yard.
Once the solution has sat for at least a few minutes, you can take your soft bristled brush and scrub away at the area to clean the larger parts of mold off and to work the solution into the stucco for best results. Then, you can take your pressure washer or garden hose and spray down the entirety of the area you just worked on: this rinse cycle prevents any color bleaching or structural damage that the cleaning solution may cause to your siding.