How to Kill Moss on Walls

Moss is a regular plant growth fed, like all plants, by a combination of light, water, nutrients and carbon dioxide.

It tends to prefer moist, shady environments and commonly can be mistaken for mold. Mosses are useful in nature for their ability to control moisture and stabilize soil, but their resilience can make growth in unintended areas a problem. A combination of physical and chemical methods can be used to kill moss.

Pressure wash or scrape the area in order to remove the moss growth.

Whether to use a pressure washer or a scraper depends on the size of the affected area. Pressure washers use the force of water pressure to clean a surface without the addition of chemicals or soaps. A scraper relies on the strength of the person using it. For a large area, a pressure washer is recommended as it will make the project go more quickly. However, for small spaces or easily damaged materials, a scraper, which allows more individual control and closer attention to detail, is better.

Bag and discard the debris.

Treat affected area with chemical moss killer according to directions and then rinse if necessary.

There are several different types of chemicals available to kill moss, including household bleach and zinc chloride. Most are considered safe but shouldn't get into water supplies. Commercial moss killers are available through garden supply stores such as Lowe's and Home Depot.

Read all portions of the label carefully and take any listed precautions to avoid injury. Gloves are recommended.

Reduce available shade and moisture to the affected area.

Reducing shade and moisture deters the moss from returning, making repetitions less necessary. Easy ways to do this are to trim back overhanging branches, keep the area clear of moisture holding debris, place an artificial light nearby and/or fix any leaks from the household plumbing.

Things You Will Need

  • Pressure washer or scraper
  • Chemical moss killer
  • Sprayer
  • Garbage bag(s)
  • Gloves


  • Rent the pressure washer. It is cheaper than buying a piece of equipment you may not use more than once.


  • Most of the chemicals used to kill moss will also kill other plants as well as being unsafe to be introduced into the water supply. Follow the directions to avoid unintended death of other plants or water supply contamination.
  • Some chemicals will stain underlying surfaces. The composition of the wall itself as well as paint or wallpaper should be factors when deciding what kind of chemicals to use.
  • The use of a pressure washer or scraper on an object has the possibility of damage. Consider which physical method of moss removal carefully prior to embarking on the project.

About the Author

Alledria Hurt is an entertainment writer from Savannah, Ga., and proud graduate of Armstrong Atlantic State University with a bachelor's in English and a master's in international studies. Now she shares her unique view with the world at large in her writing.