I have this greenish growth on my front porch (wood)... help! :)

by Jan
I have this greenish growth on my front porch (wood)... that looks mossy... What can I clean this with that will get rid of it?
  17 answers
  • Adrianne C Adrianne C on Mar 11, 2014
    It needs to be pressure washed, then repainted.
    • Jan Jan on Mar 12, 2014
      thanks!, @Adrianne C ! But I can't repaint in our subdivision. It was just done last year and it is only spots... looks like where the rain has run off trees and it is some sort of vegetative staining? There has to be something that will wash it away... I did think about having it pressure washed, though.... Thanks!
  • Jan Remling Jan Remling on Mar 11, 2014
    go to a home center and get some mold remover and scrub...then power wash and repaint. You can have them put a mold preventing agent in the paint.
    • Jan Jan on Mar 12, 2014
      Thanks, @Jan Remling. As I was telling Adrianne. . . it was just painted last year.... I really HOPE to just clean it and treat it somehow..... thanks! I will check at the local Lowe's. Maybe there is something that is 'clear' that I can 'treat' the area with??
  • Yup, mildew. Common on decks. Depending upon the type of wood and size of deck, I would not be to quick to power wash. Done incorrectly it only raises the wood grain making it rough on the bare feet. A good deck cleaning with a stiff scrub brush and rinse should be all that is needed to remove the offending material. Painting is also something you need to consider if the deck is older and in poor shape. But forget the additives as they do little to prevent mildew from coming back. If the deck is highly shaded, you need to cut back branches or what ever it is that shades it if you can. Using a good quality hose sprayer and keeping the deck clean is all that is needed to prevent this from coming back. If the deck remains damp for long periods of time, then mildew will come back. To understand why the mold is growing and why the paint additive will not work is simple. The mold is growing on the surface dirt, not the wood. Keeping it clean will prevent almost all molds from growing on the surface. In any case clean and dry and keep dry and clean. And try to prevent leaves and lots of shade from hitting the deck all day. A few hrs. of sunshine is all that it takes to keep the green stuff from returning.
    • Jan Jan on Mar 12, 2014
      @Woodbridge Environmental Tiptophouse.com - thanks! It's a small area and really fairly new. Do you recommend a cleaner in particular? The one area on the deck itself is really not shaded much at all ..... but doesn't always rec. full sun. There is a place on the handrail that a nearby tree was leaning over until I cut it a while back..... OK so ... clean and dry ---- repeat. and keep dry. Truly we did have about 4 inches of leaves dropping this fall every single day on it! I obviously need to be more diligent! Thanks!
  • Susan McMahan Susan McMahan on Mar 12, 2014
    Bleach and Brush
  • Adrianne C Adrianne C on Mar 12, 2014
    If its just in spots, I think I'd use Dawn dish soap and a scrub brush.
  • T Vaughn T Vaughn on Mar 12, 2014
    I have the same problem, and I usually have to give it a spring "Cleaning". We make a bleach/detergent mix and use a scrubbing brush, and it gets it off really good. It's always amazing how much better it looks after we're done.
  • The bleach and water method works, And they do make deck cleaners that you use by hand. No special type just read the directions and follow them. lastly if you decide to use bleach, spray down the surrounding areas with water and rinse the areas well to dilute any bleach that may get on plants and grass.
  • Adrianne C Adrianne C on Mar 12, 2014
    Harsh detergents like bleach will cut the finish and you'll have to repaint.
  • Funnygirl Funnygirl on Mar 12, 2014
    Make sure you wear gloves and eye protection
  • T Vaughn T Vaughn on Mar 12, 2014
    Adrianne C, I guess it all depends on how strong you make it, we've lived in this house almost 8 years and clean it every spring and have not had to paint yet. :) Although our doors also get the greenish dirty growth stuff too, and I have had to paint them. I think with them, I'm just going to give up on them being white doors and go ahead and paint them black.
  • AJ Wells Roofing AJ Wells Roofing on Mar 13, 2014
    I would use 50/50 mixture of water and bleach. Use a spray bottle shake well and soak the area down. Let it stand for 20 mins. or so then lightly scrub and wash away with water hose.
  • Tamara McMillan Tamara McMillan on Mar 13, 2014
    If cleaning by hand then the type of brush and pressure you use Will matter greatly. I have used a stiff bristle brush with a mixture of One part bleach to 3 parts water with some Lemon juice for good measure OR a mix of baking soda with vinegar and lemon juice. Beware however, add your baking soda very slowly as it will definitely foam when mixed with the vinegar. Lastly good old Dawn or heavy duty dish liquid and water works well.
  • Wendy M Wendy M on Mar 13, 2014
    Bleach and a brush work the best. I have the same problem and the bleach helps kill the mold also. I even use a toothbrush to get the corners. I use a spray bottle filled with half bleach and half water.
  • Lynnpaulus Lynnpaulus on Mar 13, 2014
    TCP....better than bleach and no fumes...Lowes or home depot....dry powder, mix with water and scrub.....(or, spray and let stand for awhile ....then wipe down) Love this stuff !
  • Carmen Carmen on Mar 14, 2014
    I would use baking soda. It works for me. :-)
  • Ellen Ellen on Mar 15, 2014
    We have to clean our porch every year. I found Simple Green works well against mildew. I spray it on and let it sit a few minutes and then rinse or scrub as needed.
  • One other note to add to the conversation. Its important to know that some deck materials may not fair so well with some of the suggestions that are made to clean it. While one may work really well for one type of deck material, it may stain or bleach out the color in another. Wood decks tend to take a punishment from pretty much all of the suggestions and you may have great luck using anyone of them,, but if you have a plastic or man made deck of some sort, check with the manufacture of that product. Some cleaning done wrong will void any warranty they have on it.