How can I kill mildew and mold growing on composite decking?

Hello Deb,

Use Spray and Leave or Wet and Leave available online or in stores.

Hi, Deb32627038!

I normally use outdoor bleach diluted with water and a scrub brush, then spray it off with a hose. The deck should be wet first and the bleach solution can be applied with a sprayer (the type normally used for weed killer) then rinsed off. I hope this helps!

Hey Deb,

This should help you:

https://www.hunker.com/12174936/how-to-remove-mold-mildew-from-trex-decking

Clean with white vinegar. It will kill the spores. Then spray with wet & forget outdoor to deter re-growth. Spray again at the first signs of "green".

Wet and Forget, Simple Green deck wash.

Hi Deb, hope this helps you

1. Use a pressure washer to remove as much of the mold as possible.
2. Mix a solution of 2 parts of vinegar and 1 part of water in a bucket.
3. Pour the solution on the mold and sprinkle baking soda all over the area.
4. Allow the vinegar and baking soda to sit on the area for at least 20 minutes. then rinse well

A power washer is a great tool. Wet it and Forget it is my go to for a project like yours.

Go to Home Depot get mold kill for the deck and get Thompson’s weather seal clean the deck with the mold cleaner with a scrub brush then apply Thompson’s water seal