What Should I Do If My Siding Is Turning Brown?


If you notice your vinyl siding is turning brown, you probably have a moisture problem. Brown spots on the exterior walls of your home can also be caused by dirt, mildew or algae.

Fortunately, it’s easy to diagnose and treat any type of staining that might affect your vinyl siding. So if you’ve seen cosmetic damage on the outside of your home and don’t know what to do about it, read this article for tips and advice from professional contractors.

Brown patches on vinyl siding could indicate mold or fungal growth.

Step one – Determine cause of stains

A common problem which can cause your vinyl siding to turn brown is excess moisture. If your home has a problem with moisture, it’s best to begin by checking the exterior walls for areas that might be wet or damp.

You should also check for mold and mildew growth, plant overgrowth and dirt accumulation which can form into bubbles on the surface of your bricks or siding – these often occur after rainstorms when debris gets caught in between your vinyl panels. Finally, look out for algae stains, which are caused by an organism that grows easily in moist conditions such as those found underneath roof shingles where it can thrive without being disturbed. Algae may appear either black or greenish-black and will create dark stains on house surfaces that haven’t been washed in a while.

Step two – Wash exterior surfaces with solution of water and bleach

If you have determined that the problem is mold or mildew, you should start by thoroughly cleaning your vinyl siding using a strong solution of water and bleach. Simply mix one gallon of warm water with 1/4 cup chlorine bleach, then pour this mixture into a hand-held spray bottle and apply it to all areas of your home’s exterior walls where stains are present. For best results, leave the mixture on for at least 30 minutes so that it can penetrate deep down into the material and kill off any fungus or algae spores that might be causing your staining problems. You may need to repeat this process if there is stubborn debris still clinging to your vinyl siding.

Step three – Encase exterior walls in a breathable membrane

If you have determined that your brown spots are caused by dirt, algae or mildew, it’s important to take action right away so that the staining does not worsen over time. One effective solution is to apply an exterior wall coating using a breathable membrane which will help prevent future stains from forming. This type of coating works by encapsulating each brick or panel of vinyl – it acts as a protective barrier to keep moisture and other damaging substances from penetrating through your home’s outer walls. In order for this solution to work effectively, you should use a high-quality product produced by a reputable company such as American Weather Star Coatings or All Shield.


If you follow these steps, you should be able to effectively prevent your vinyl siding from turning brown due to moisture or other external factors. And if your staining problem is more severe in nature and beyond the treatment of these solutions, you may need to hire a professional contractor who will be able to clean and restore your home’s exterior walls using specialized equipment. Good luck!