Platform Decks

How can you remove the green algae stuff (mould) off decking?

The decking (verandah) has got some green algae growing on it... how can I get rid of this? have tried both pressure washer and scrubbing brush.. but not much luck.

Public Comments

1. A pressure washer will do the job nicely.
2. Try using a bleach water solution and a scrub brush or a broom to remove the mold and kill it out.
3. if you mix chlorine bleach and water, 50/50 then put it in a sprayer and spray the entire area. leave it sit for about 10-15 minutes and then wash off with a garden hose. you may have to scrub the thick areas with a brush and respray then rinse. bleach is the only thing that can remove and prevent any further mold growth.
4. There are several products on the market designed to clean decks and remove algae, and they are sold in most hardware stores. I understand that ordinary bleach will do it, too, but don't know how much it should be diluted with water or how long to let it sit before you hose if off. However, bleach is cheap, so you could try it (but be sure you wear really old clothes since you'll probably splop some on yourself!)
5. Hi there, I have ran across the mold problem on different surfaces before. Have you heard of simple green cleaning solution? Well, if you spray or apply it strait or cut by 50% with water and let it sit for a half hour then scrub. Spray it off with the pressure washer then. It has always worked for me. It is just a suggestion but it should help. Let it dry and preserve the wood with a stain or Thompsons water seal. Hope this might help, Mike
6. I don't know what type of pressure washer you were using, but even the small electric ones have enough pressure to cut grooves in decking & with the right tip, will clean anything from the wood. Plain water in the pressure washer is really all you need Once it has been cleaned & allowed to thoroughly dry it should be treated with a penetrating sealer like CWF. Mold & mildew will grow on surfaces that are shaded & don't get any sun. Oil type treatments, like CWF, are usually good for 1-2 years, then pressure washing & re-treatment will again be necessary. For occasional spot growth of mold, a Borax & water solution is better at killing surface mold & it does not discolor or damage like bleach does. Good luck...