It may be difficult to understand why a deck looks to weather so quickly. It turns gray from the weather and fades quickly. Unlike your siding or roof, there is no place for snow, ice, and rain to trickle down. Your deck is horizontally exposed to the elements, meaning that any snow or rain buildup on the deck will not slide off. Decks can have very large surface areas, allowing them to potentially catch very heavy loads of snow on top of the grills, chairs, and tables already on them. Water and snow has to evaporate or melt all by itself on these decks since there is the tendency for precipitation to pool and accumulate on decks, causing the gradual wearing away of the beautiful wood that the deck was built with.
Due to this fact, it is extremely important to apply a wood stain that will not only protect your deck from rain and snow, but the damaging UV rays from the sun. The sun is a real culprit when it comes to decks. Because they have such a large surface area, it has the tendency to catch incredible amounts of UV rays, promoting the graying and general deterioration of the wood over time.
A clear or transparent wood stain gives you much less protection than a semi-transparent or opaque wood stain because there is less pigment between the wood and the sun. You can absolutely prevent ugly graying and stain fading over time by applying a semi-transparent or opaque wood stain to block UV radiation from penetrating the wood. An opaque wood stain is just that, opaque, and does not allow the grain of the wood to be visible. It does however accentuate the wood's texture. If you are looking for a stain that allows most of the grain of the wood and all of the texture of the wood to show through, then a semi-transparent stain will fit your bill. It does not protect the wood as well as an opaque stain does but provides more protection than a clear stain. Even clear stains will alter the look or color of the wood, so find a stain that will accentuate the color of the wood and provide the most protection.
It is prudent to look for a deck stain that provides some type of UV protection, or else the sun will start fading away your expensive deck staining project the moment you apply it. Just as the sun fades the look of outdoor rugs, it fades the pigment in your deck stain. This vicious circle can certainly be a pain for homeowners, but with the proper care, can be prolonged to prevent too frequent maintenance.
Source by Clay Lamb