Why Protect Wood
Wood has the ability to offer dozens of years of use when certain conditions are met. However, when certain conditions are present the development of wood-degrading organisms will detiorate the integrity of the wood, shortening its life. The principle organisms that degrade wood are fungi, insects and bacteria. The growth of fungi depends on temperature, moisture and air. This process is evident through black, green and gray discoloration of the wood. Mold fungi can increase the absorbency of wood, allowing the wood to maintain moisture, which in turn can lead to wood rot.
The UV(ultraviolet radiation) rays of the sun break down the cell structure of the wood causing weakening and a decomposition of the surface. The process is known as photo-oxidation. This is evident with the wood turning a gray color exposing the dead fibers. These fibers need to be removed prior to coating, as they will inhibit the effectiveness of the coating.
Exterior wood should be treated as soon as 30 daysafter installation for cedar and 90 days for pressure treated lumber. This has been a widely debated topic over the years. The reality is that within 1-4 weeks there is lignin damage caused from the UV rays of the sun.
The effects of wood left untreated are:
- Gray discoloration of wood surface
- Warping – twisting of the board
- Checking - surface checks are failures that occur in the wood rays on the flat sawed surface of the lumber. They normally occur in the initial stage of drying when relative humidity is too low.
Common Wood Types
Pressure treated pine is the most common type of wood used in deck construction. Pine is lightweight, moderately soft and low in strength, shock resistance and stiffness
Cedar is a common wood type used in deck construction and home finishing. The benefits of cedar are its durability due to its natural protection from insects, mold and mildew. It has a pleasing aroma and is easily shaped and sawn.
Resistant to decay, termites and rot. Carries a high fire rating. An extremely dense, tight grained wood. Generally a deep rich brown with some pieces displaying red and amber hues.