Decks, Patios, Porches and Docks - restaining deck

I have a 15 year old deck that I want to restain this summer. Do I pressure wash off the old stain or sand it off before applying the new stain? Also, do you suggest any other type of preparation? Sealer? primer?
Thanks.

Pressure wash the deck and let it dry a few days. Then apply the stain. Depending on what you use for a stain, either nothing else is needed, or you may have to apply a sealer later. I would check that out thoroughly before buying any stain. A $20 or $25 per gallon product like Super Deck is less expensive than a $15 per gallon stain and a $20 per gallon sealer, not to mention faster. Get the advise from the retailer.

Thanks for the help, Lefty.

I'm not sure I'd pressure wash my deck. There's too much chance of gouging the wood, especially if it's something soft like redwood. The deck cleaning and brightening products usually do well without pressure washing.

I'd sand anything that looks like it's going to put a splinter in your toe.

What stain you use depends on your climate. Some are better for dry climates where ultraviolet is the main enemy. Others are better for wet climates where rain is the main enemy. I agree with lefty -- get advice from your local retailer. Whatever you do, don't use any paint or urethane.