How to Remove Exterior Mildew Stains

Image demonstrating mildew removal from exterior siding. Image demonstrating mildew removal from exterior siding.

Make sure to remove any mildew stains before you paint your home's exterior.

For Best Results:

Make sure to dampen the areas to be cleaned prior to applying the cleaning solution

Allow sufficient time for the cleaning solution to work (10 - 15 minutes).

Suggested Tools & Supplies
  • Bucket
  • Hose
  • Ladder
  • Pressure Washer
  • Protective Apparel
  • Pump Sprayer
  • Rags
  • Scrub Brush
  • Step 1

    Using a garden hose or a pressure washer, wet the mildewed area with water.

  • Step 2

    Using a pump sprayer, apply BEHR PREMIUM® All-In-One Wood Cleaner to the mildewed area.

    Tip: Prior to applying the cleaning product, dampen the surrounding grass, plants, and other vegetation with water.

  • Step 3

    Reapply the cleaner as needed to keep the surface wet. Allow the solution to remain on the surface for 10-15 minutes. Scrubbing may be required on severely stained surfaces.

  • Step 4

    Thoroughly rinse the surface with water. Allow it to dry.

    Tip: For non-painted wood or new wood, apply BEHR PREMIUM All-in-One Wood Cleaner to the wet, rinsed, treated surface. Do not allow the surface to dry prior to applying the product.

ADDITIONAL RESOURCES
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What sheen do I need?
8 Oz. Sample
1 Gallon
1 Quart
5 Gallon
The following product(s) is required to properly prep and pre-treat wood prior to any stain project.
Required product
BEHR PREMIUM ALL-IN-ONE WOOD CCCC
$0.00
The following product(s) is required to properly prep and pre-treat wood prior to any stain project. Only available in store at Home Depot.
Required 3rd party product
BEHR PREMIUM ALL-IN-ONE WOOD CCCC
The 9 in. x 1/4 in. Polyester Adhesive Roller Cover has a hard texture, making it ideal for applying all types of adhesives to smooth surfaces. It can be used for stippling and applying sand paints.
The following product(s) is recommended when stripping is needed.
$0.00
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