What Causes“Fuzzy Wood”

We conducted another dock inspection this week. The dock pilings showed significant signs of marine borer damage below the surface and delignification (fuzzy wood) above the waterline. This “fuzzy wood” is a direct result of the wicking process.

Wicking occurs when saltwater is drawn into the wood piling. The water travels up the grain through the xylem cells. Once above the waterline, the water evaporates, leaving salt crystals. Overtime, the salt residue can expand, damaging the wood and causing it to appear fuzzy. This process of destroying the lignin (the “glue” that binds wood cells together) is known as delignification. Overtime, the timber pile is gradually weakened and can eventually collapse.

Even pressure treated (ACA, CCA) wood can be subject to wicking because of the limited penetration of the chemicals into the wood.

Sadly, because these pilings were not on a regular maintenance plan, they will all have to be replaced. Wrapping pilings combined with regular inspections (annually or after a major storm) can extend the life of your dock and save money in the long run.

Timber piles appear fuzzy when lignin, the “glue” that binds wood cells together, is destroyed by the delignification process.

Because these pilings were not on a regular maintenance plan, they will have to be replaced.

The wood on this piling was so soft, oyster clusters were easily removed by hand, taking shreds of wood along with it.