Enzymes, wood-decay organisms

Significant Decay. Wood decay organisms produce enzymes that break down the chemical structure of the wood and provide food for the decay s growth. This breakdown results in a progressive loss of the wood substance. The process is reflected in reduced density and strength, increased fluid permeability, and altered color and texture. 

The cardinal rules for proper use of wood can be stated simply keep wood dry, and, if you can t keep it dry, use naturally durable or preservative-treated wood. The first rule is based on a simple biological principle liquid water is needed in wood cells to provide a medium for diffusion of the enzymes or other metabolites by which wood-decomposing organisms digest the wood substance. If there is no liquid water present inside the wood cells, there will be no medium for diffusion, and therefore no biological decomposition except for certain insects of relatively minor importance. Thus, as long as wood is kept below its fiber-saturation point (about 27% of its dry weight), it will never decay. 

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