How Semi-Transparent Stains Work

• Semi-transparent oil-based stains contain oil, pigment and solvents. This combination of ingredients allows the stain to penetrate deeply into the wood and protect it from solar ultraviolet, or UV, rays and water infiltration. Over time, the UV will break down the chemical structure of the stain and outdoor exposure will cause the wood to dry out and begin showing surface cracks in the direction of its grain pattern.
  
  

How Solid-Color Deck Stains Work

• Solid-color stains are essentially a stain/paint hybrid. Like other stains, they penetrate into a wood's surface and usually come in shades of brown, tan or gray. Like a paint, a solid-color stain features ingredients that hide the substrate's natural color variations with a uniform color of its own. Unlike paint, solid-color stains do not form a film on the surface which would conceal the wood's natural texture.
  
  

Applying a Solid-Color Stain

• Most manufacturers recommend applying solid-color stain over a clean surface using brush, roller or sprayer. Ideal surface prep might involve applying a deck stripping chemical to the wood using a pump sprayer and following up with a pressure washer treatment. Once the decking lumber dries completely, it will be ready for the solid-color stain.
  
  

When You Can Bend the Rules

• Stripping may not actually be necessary if the prior coat of stain has already broken down from extended exposure to the elements. If the existing coat is a semi-transparent stain, for instance, its expected lifetime is typically three years on horizontal surfaces. After that time, the solid-color stain will likely have no trouble adhering to the deck even if the existing stain is not removed.