Marine Treatment for Timber Piles

Timber piles are preserved to protect them from marine organisms.

Timber piles are part of many types of structures that come into contact with the water, including piers, jetties and wharves. These can be in freshwater, such as lakes or rivers, or in the salty water of ocean shores and inlets. Timber piles are typically preserved with chemicals in order to protect the wood and extend their lifespan.

Protection Against Marine Organisms

Timber piles that are underwater are at risk of attack from marine organisms. Organisms like ship worms bore into the wood, weakening the pile from within. Others, like gribbles, attack the outside of the pile, encouraging ocean waves to wash away significant amounts of the wood.

Treatment Techniques

After identifying potential marine organisms in the area, it can be determined what chemicals and in what strengths are best for the situation. Creosote, a mixture of creosote and tar, ammoniacal copper arsenate and chromated copper arsenate are common pile preservatives.

Increasing Pile Lifespan

Water organisms are extremely destructive to wood. It can take as little as six months to destroy a pile that is one foot in diameter. Properly treating this pile extends its lifespan to 25 years in southern environments and 50 years in northern environments, according to the Timber Piling Council.

References

• U.S. Army, Corp of Engineers: Coastal Engineering Technical Note
• Timber Piling Council: Timber Pile Properties