I am trying to select a good wood deck finish. I have found many info
about the various types of deck finish that are currently available in
the market. One thing that I cannot find info on is the type of
annual maintenance that I need to do for the deck if I choose that
type of deck finish. According to one of the DIY article that I find
in the net, I am supposed to clean and apply a coat of finish on the
deck yearly. But I am wondering if this is only applicable for some
type of finish but not other. I don't think I can simply apply a coat
of finish over existing finish; I believe I need to at least sand the
surface first; otherwise, the finish won't stick that well, right? If
I continue putting more and more coats of finish, I am afraird that
the finish will be too thick, and may start peeling, right?

Currently I am considering between using "clear finish with UV
protection" and "semi-transparent stain". Please tell me the kind of
annual maintenance that I need to do if I choose either one of them.
I will greatly appreciate if someone can tell me the step-by-step way
to do this annual maintenance. Then I can evaluate whether this kind
of finish is really appropriate for me.

By the way, what I want from the deck finish a (1) prevent the
pressure treated wood deck from turning grey in order to maintain the
natural wood color or have a nice redwood color, (2) reduce water
absorption into the wood, (3) reduce mildew on the wood surface, (3)
annual maintenance is OK, taking too much time to do each annual
maintenance is not OK.

The current wood deck finish that I have on the deck is semi-
transparent stain. I pressure washed the deck and then applied the
stain. I didn't do any annual maintenance because I don't know if I
need to do this and I don't know how. By the end of the first year,
stain had started coming off in the center of the deck (high traffic
area). By the end of the second year, mildew started growing in where
the stain had come off. Then I using stain remover to remove the
stain, and did that over. But the same thing happened (just faster
than before). I figure that I need to do some annual maintenance to
keep the finish; this prompts me to ask around here.

Thanks in advance for any info.

Jay Chan