Treated lumber ( stubborn something coming through)

Hey all,

I’m still new here so I’ll try to be brief and to the point. I stained a deck a year and a half ago after treating it with a deck wash solution. Not the owner says that there are green boards. I will include pics of the effected boards.


It’s mildew and extractive bleeding (tannins, etc.) I’d say a year and a half is pretty good considering no stain/sealer will stand up to weathering/UV exposure forever. What does the owner want you to do about it? I would think he/she simply wants the deck done again at regular rates since I’m sure you didn’t give something crazy like a Lifetime Guarantee.

Do the deck again and let the owner know you can keep this from happening again with your maintenance program.

Hey David thanks for your reply! the owner wants the two areas redone. I not sure the best way to do this without messing with the other surrounding boards. I’m no expert in this area. I’m thinking to brush a bleach solution into the tow areas then PW. I’m using Ready Seal wood stain.

Thanks for you reply,

Ken it is most likely mold or mildew. It could also be the cooper from the pressure treating leaching out if the wood was treated after 2003. I would wash with a mild house wash mix. Whenever we stain decks we tell the people they need to be washed annually to maintain their appearance. We also tell them verticals need to be stained every 2 years and horizontals every 4 years.

What would you consider a mild house wash mix?