Deck Stains
Clear sealers protect the wood from water damage. Those with additives that resist mildew formation, insects and fungi growth are best. UV blockers help reduce damage caused by the ultraviolet rays of the sun. Sealers with pigments offer the same protection but change the wood color slightly. Sealers can be applied under or over stains and under primer and paint.
Deck stains, unlike sealers, are formulated primarily to alter the appearance of the wood. Semitransparent stains allow more of the wood grain to show through but wear more quickly. Heavier bodied deck stains contain more of the pigment and hide more of the wood grain.
The rule of thumb in the world of deck stains, sealers and paints is:"You get what you pay for." The better, more expensive finishes contain solvents, repellents, preservatives and pigments. They tend to last longer than the less expensive products. They will cost more per application because the deck will soak up more. However, in the long run they will save time and money because they will need to be applied less often.