With wood, the most important step for long life and low maintenance is to block moisture from soaking in.  This requires a seamless barrier also called a “waterproof membrane” and can be done in a couple of ways. The spray-on nature of ArmorThane polyurethane and polyurea materials allows for easy coating protection. Because decks are often built with strips of boards, one approach is to encapsulate each board before putting a new deck together.  Unlike surface coatings, this prevents damage caused from water seeping between boards and the moisture that can build up underneath the structure. This method also preserves the architectural look of a slatted deck or balcony.  The problem is that it cannot be used on an existing deck, unless the boards are wide enough for complete coating between the slats. The best approach is to use large sheets of plywood and seal all visible seams.  When ArmorThane polyurethane or polyurea is sprayed over the entire structure it creates the seamless membrane. To ensure a seamless waterproof barrier, an area to watch is where the deck or porch connects to another structure such as the house, patio, fence or even supporting beams.  Watch for the next article on how this works best.