Coastal Living and the Effects of Sun and Water on Wood Furniture
Protecting wood surfaces in a beach, water front or other humid environment is a challenging task. Being in Alabama, we know this well. You are faced with numerous variables that contribute to erosion and degradation of the substrate including sunlight, wind, moisture, salt, and sand. The two most destructive environmental variables to an exterior coating system and wood are sunlight and water.
Sunlight is the major cause of damage to a number of materials, including plastics, textile, wood, coatings, and other organic materials. The type of damage, such as loss of gloss, chalking, elasticity, adhesion, and color change, varies depending on the material sensitivity and the spectrum of sunlight. Spectral sensitivity varies from material to material. Ultraviolet light is responsible for most damage to exposed wood because it changes or destroys the wood’s lignin, a component of wood that hardens and strengthens the cell walls. The scientific term is photo-oxidation. Opaque finishes like paint and solid body stains are very efficient in blocking all of UV light from hitting the wood. That’s why when they peel off the freshly exposed wood may still look bright. On the other hand the objective of transparent stains is to allow the character of the wood to show through the finish. Shou sugi ban is an ancient Japanese method of burning wood—specifically cedar, but it works on other species—that we use on our Hyo tables and Beam Benches, that work both indoors and outside.
The second challenge for wood in a coastal environment is moisture. Coastal areas are notorious for their high relative humidity and pop-up thunderstorms. Keeping wood dry is the goal to protecting its long term integrity. If wood remains wet for long periods of time without drying out, conditions are favorable for the formation of wood decay fungi, the precursor to wood rot. Four conditions are necessary for the development of wood decay producing fungi. Eliminate any one of these and decay fungi cannot survive: oxygen, temperature (40° - 90°F), moisture content in excess of the fiber saturation point (> 25-30%), and a suitable source of energy and nutrients (that is, the wood).
You can't completely stop or reverse the weathering of exterior wood, but you can slow the process dramatically by using the right type of finish system and a proactive game plan to combat the environmental elements.
Here are the basic ways to combat the effects of weathering.
- PLACEMENT: Wood outside is always hard. By far the most effective method is to keep wood surfaces in the shade as much as possible. For example, by extending roof overhangs or constructing roofed porches around the home. Keep all vegetation at least 24 inches away from wood surfaces to allow for adequate ventilation and drying out of these surfaces.
- PROTECT: Use an exterior clear topcoat. Fill all upward facing checks, cracks in wood, with a sealant. Alabama Sawyer has a tool box of options. Depending on your project, we will select the best option.
- MAINTAIN: You can’t get out of this. Perform an annual inspection of the coating system as a proactive maintenance approach. Clean the finish systems at least once a year to remove all foreign debris for the surface of the finish system and extend its longevity.