Protecting piles from decay; end treatments

Millions of dollars are spent each year to replace decayed marine piling. The primary avenue of decay infection is through the ends where untreated wood is exposed after piles are cut off. Thus, several fungicides were evaluated for their ability to protect the top cutoff end of creosoted Douglas-fir piles from decay. Supple­ mentary treatment with a 20 percent ammonium bi­ fluoride solution or Osmoplastic provides at least 5 years of protectionagainstdecay ina highdecay hazard climate. Pile tops treated with copper-8-quinolinolate, sodium borate, ammoniacal-copper-borate, sodium pentachlorophenate, and pentachlorophenol were decayed without a cap and, therefore, should only be used where a cap can be maintained.