“Water beading” simply indicates the presence of a water repellent additive in your product. Unfortunately, it takes more than surface water repellency to protect your deck from the elements. To really do the job, you’ll need to use a product which penetrates the wood cells and encapsulates the wood fibers with a protective resin. Choose a product which will provide your deck with deep- penetrating protection from the damaging effects of the sun’s ultraviolet rays, as well as from rain and snow. Also, look for products which provide mildew resistance.