what's the best way to treat a deck?
Answers:
I am an engineer and my first introduction into this was when my buddy decided he would refinish his deck using his own "common sense" and cheap materials at hand. He ended up putting motor oil on the deck and completely ruining it. (He later saved money on lawn fertilizer by buying rotted waste from the city. Every time it rained it smelled.....well, you get the picture!)
THE BASICS
You will have to clean it first with bleach and a power washer. Let it dry. Your Home Depo has products to treat it. I would avoid varnish because it can peal off. A stain and an oil would be my preference. You will probably want to repeat your final procedure every one-two years.
But, refinishing a deck the right way is a bigger job than it may first appear to be. It will pay to map out what your deck needs and how much time and money you will want to spend first. Since the actual work is so time consuming and has to be repeated in the future, this step will reap big rewards if you do it right.
Really good websites that will answer these questions and much more are listed below:
How do I clean REALLY old, grimy, wood kitchen cabinets?