Cleaning Vinyl Siding: Mildew and Mold

What You'll Need
Pressure washer
Cleaner (cleans mold and mildew)
Scrubbing brush
Extension handle
Garden hose
Paint brush

If your vinyl siding is turning black, green, grayish, fuzzy or powdery, it might be vinyl siding mildew or mold, which is a common problem in humid regions. If it is not a weather problem, check for rain water falling down onto your siding the wrong way, for leaks in your gutters, or sprinklers that shoot water onto your siding at regular intervals. There are several options for battling mildew or mold on your home siding.

Step 1: Identifying the Problem

If the problem area is above reach or not eye-level, use a ladder to get close to the stained area and examine closely. Mildew or mold can be green, gray, black, brown, powdery or fuzzy. It should be easy to wipe off using a rag. Go out on a rainy day and check to see if any rainwater falls over the edge of the roof onto the problem area. It is better to get to the root of the problem so that it is not repeated a few months later.  

Step 2: Using Pressure Washer with Cleaning Solutions

Pressure washers can be rented, if buying is not an option for you. There are also professional home exterior washers who can pressure wash your siding for you. Some experts do not recommend pressure washing frequently because the high pressure with which the water is pressed against the cracks and fissures on the walls of your house might cause more harm than good. You can treat the area previous to pressure washing it, or some pressure washing machines allow you to pre-treat the water so that the cleaning solution shoots out with pressure to clean the soiled area. Always test all cleaning solutions on a small corner of the siding and wait to see if the area changes in color or texture. Rinse area with water and allow to dry overnight.

Step 3: Using a Scrubbing brush with Cleaning Solutions

You can buy a store bought cleaning solution or use bleach diluted with three parts water on the molded area of your siding. Take a scrubbing brush attached to an extension handle if the molded area is out of reach and brush the area thoroughly with the cleaning solution. Use your garden hose to rinse with water and allow to dry overnight.

Step 4: Using Cleaning Solutions and Paint

Some store bought cleaners are harsh, or even bleach used inaccurately might have changed the color of your siding at the problem area. If the stain proves too hard to remove, the last option is to repaint the whole exterior siding. Pick a dry sunny day to paint. Paint first with primer, allow to dry, and then paint with regular exterior paint. Don’t try to finish the whole house on the same day. Pick a section at a time and pace yourself so that you are not too overwhelmed with the workload.