I'm a former dock & seawall contractor, on the Florida Gulf coast.
CCA (copper chromated arsenic) is the drug of choice for wood preservation. The numbers .25, .40 and 2.5 refer to the pounds of chemical per cubic foot of wood being treated. .40 is "OK" for damp ground, .80 and higher are best for fresh water immersion. 2.5 and 4.0 is salt water stuff.
Use the yellow pages- call a wholesale distributor who can recommend a dealer to sell you decent material. Eddie is entirely correct about 4x4 6' o.c. Easy to handle; smaller base hole. If you're not dealing with rock or clay, you should be able to jet those with a garden hose or (preferably) a 2" centrifigal pump.
If swimmers use the dock, consider the trex type deck- no slivers!
mike
CCA (copper chromated arsenic) is the drug of choice for wood preservation. The numbers .25, .40 and 2.5 refer to the pounds of chemical per cubic foot of wood being treated. .40 is "OK" for damp ground, .80 and higher are best for fresh water immersion. 2.5 and 4.0 is salt water stuff.
Use the yellow pages- call a wholesale distributor who can recommend a dealer to sell you decent material. Eddie is entirely correct about 4x4 6' o.c. Easy to handle; smaller base hole. If you're not dealing with rock or clay, you should be able to jet those with a garden hose or (preferably) a 2" centrifigal pump.
If swimmers use the dock, consider the trex type deck- no slivers!
mike