Carpentry and Woodworking - Saving an Old Deck

New homeowner of 16 year old twnhse. My stairs and deck does not have any paint, but has a grayish look to it. Not properly taken care of in the past, so the wood is starting to mold in some spots (very slippery/looks terrible). Is there something I can do to help restore the wood or am I looking at replacement as the ONLY answer.
PLEASE HELP!!

I'm no expert,but I was at the local lumber yard the other day,and saw some stuff called deck re-new or something like that.It is supposed be awesome stuff!There are different things to combat various problems.I just built my deck,so don't need it yet :) Good luck to you.

Your deck is likely made of cedar.It naturally weathers to a gray finish if left untreated. Some prefer this over staining. If the wood is not punky there is no need to replace. If you want to stain the deck, it will need to be cleaned & given enough time to dry. Your local building store will carry the necessary products. Follow directions for wash & stain. To remove the mold, wash the deck with a ten part water, one part bleach solution.

Could also be just treated pine which also
tends to weather to a gray color. Best
stuff I've seen comes in a powder that you
mix with warm water and then apply by
spraying or brushing. It foams up for a while and then you give it a little scrubbing with a stiff brush and rinse it off. Can't recall the brand name, but it comes in a plastic container about the size of a peanut butter jar with a yellow label and it is stronger than just plain bleach. Pressure washing also works very well in conjunction with whatever product you use.
Good luck.