Never

This all comes down to a professional or DIYer.

Bleach used the right way 20 to 1 I would say is fine for wood, But bleach rots wood fibers just like it will do to your clothes.

I am hearing more and more about this Oxigenated Bleach? I understand it's good for trex decks. A customer I had wanted me to just wash his deck and he was going to seal it. It was a real easy deck and down the road so I lowballed him for the fun of it. Seemed like a nice guy. Next thing I get this letter in the mail from him with a sheet of how to clean with Oxigenated Bleach? Whaaa????? I told him he asked for a quick wash and then he started to go technical on me. I told him some one eles uses the bleach and he should call him. He called back a few days later saying he was going to forget the bleach... Yeah he saw the new price. No thanks red flag!

Nope no bleach

Why do I like doing Deck Refinishing? I like taking somthing that looks like crap and making it look like new. Why? Good question! I hate painting! Deck Refinishers don't paint!