How to clean green mould off canvas awnings

Updated February 21, 2017

Canvas awnings are usually mounted over doorways, windows and patio areas of homes and buildings. The awnings serve to shade the areas from direct sunlight, protect people from rain showers as well as enhance the outer appearance of the home or building. Canvas awnings require regular cleaning, just like any other outdoor fabric. If the canvas awning has developed green mould growth on it, a more aggressive cleaning procedure must be performed.

Remove the top from a chemical sprayer and fill it with an awning cleaning solution. These solutions are available at home improvement shops.

Walk under the awning and point the wand of the chemical sprayer at the underside of the awning. Spray the entire underside of the awning with the cleaning solution, paying special attention to the areas of mould. Depending on the height of the canvas awning, a ladder may be required to properly reach the areas of mould.

Allow the cleaning solution to sit for five to 15 minutes.

Attach an 20-cm (8-inch) scrubber brush to an extension handle and scrub the entire underside of the awning.

Rinse the underside of the awning using a garden hose with a sprayer attachment. Spray from the top of the awning towards the bottom so that the soap runs in a downward direction.

Place a ladder next to the canvas awning and repeat the cleaning process with the top part of the awning. Work in small sections at a time to prevent the cleaning solution from drying on the canvas.

Pour out the cleaning solution from the chemical sprayer and fill the sprayer with 50 per cent water and 50 per cent bleach.

Spray the bleach solution onto the areas of mould and mildew and let it sit for two to five minutes.

Rinse the entire awning twice using the garden hose to remove all traces of the bleach from the canvas awning. Any residual amounts of bleach may discolour or damage the canvas.


Wear a mask and eye protection when cleaning the awning to prevent the cleaning spray and bleach from splashing in the eyes or mouth.

Do not wet the awning prior to applying the cleaner, as this will decrease the effectiveness of the solution.

Things You'll Need

  • Chemical sprayer
  • Awning cleaning solution
  • Ladder
  • 20-cm (8-inch) scrub brush
  • Extension handle
  • Garden hose
  • Sprayer attachment
  • Bleach
  • Water
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About the Author

Kimberly Johnson is a freelance writer whose articles have appeared in various online publications including eHow, Suite101 and Examiner. She has a degree in journalism from the University of Georgia and began writing professionally in 2001.