Understanding How Deck Stain Works
The best way to describe how a deck stain works is to basically compare it to regular wood stain. When staining an old piece of furniture, a door, or some wood trim you would be sure that the wood is clean and bare with no remnants of old stain or paint on the surface. Staining over old stuff would not give the best appearance and the wood stain would not penetrate the wood properly. In some cases the stain would not even dry or cure and would just wipe right off any areas where it was applied over the top of anything but bare wood. Well the same goes for staining a wooden deck. The wood must be clean and bare for the deck stain to penetrate and do its job correctly. But yet people and even contractors, for whatever reason, get lazy and applied deck stain over old deck stain all the time and then wonder why it does not hold up. Deck stain is meant to penetrate the wood fibers to lock out moisture. The deck stain should be absorb by the wood just has water wood if it were spilled onto bare wood. The stain dives deep into the wood so water and moisture can not. The reason this increases the longevity of the wood is because moisture would cause the wood to swell and then has the wood dries out it would shrink. This constant action and reaction causes the wood to split, warp, and crack.
