May be used to satisfy+

  • AWPA Standard M4
  • IRC R317.1.1
  • IBC 2303.1.9

+ when diluted to a 2% metallic copper solution (refer to dilution chart)

The appropriateness of the preservation system for field treatment shall be determined by the type of preservative originally used to protect the product and the availability of a field treatment preservative. Because many preservative products are not packaged and labeled for use by the general public, a system different from the original treatment may need to be utilized for field treatment. Users shall carefully read and follow the instructions and precautions listed on the product label when using these materials Copper Naphthenate preservatives containing a minimum of 2.0% copper metal are recommended for material originally treated with copper naphthenate, pentachlorophenol, creosote, creosote solution or waterborne preservatives. Use of copper naphthenate preservatives with a minimum of 1.0% copper metal is appropriate in those regions of the country where the higher concentration material is not readily available.

Copper Care Wood Preservatives' Cu-Nap Concentrate (8% Cu as metal) is a liquid Copper Naphthenate wood preservative that can be diluted with diesel or mineral spirits. It is widely used as a dip treatment for fence posts using a 24-hour soak. Cu-Nap Concentrate is labeled for the treatment of posts, poles, lumber, siding, boxes, roof shakes and shingles, fence pickets, landscape timbers, cellulose textiles and cordage. Apply by brush, dip, or pressure treatment. Cu-Nap Concentrate is a cost effective solution for large volume, commercial users. For dilution and other detailed information, refer to the product label, the product flyer, or call us.

Cu-Nap Dilution Chart

Dilution with #2 Fuel Oil

(Gallons of oil per 1 gallon of Cu-Nap Concentrate)

Cu-Nap Dilution Chart with #2 Fuel Oil

Copper Naphthenate provides protection against wood decay and the superior water repellent qualities of an oil borne wood preservative. Copper Naphthenate treatments result in wood that is cleaner to the touch, with minimal excess preservative coming in contact with the environment. Copper Naphthenate is the green choice in preservatives because it is not a restricted use pesticide. With durability equal to or better than other preservatives, it is a great choice for bridge timbers, barn timbers, glulam beams, salt storage domes, protector boards and highway railings. For many applications copper naphthenate is the best wood preservative available to contractors and builders. Use copper naphthenate when wood will be in contact with the ground and as an end cut treatment when applied to cut pressure treated wood.

Formosa Subterranean Termite Protection

University of Hawaii study demonstrates effective protection. Situation should be considered a severe deterioration hazard and the high retention for Use Category 4C should be specified.

Reveals Natural Wood Grain

The bright green color of wood freshly treated with copper naphthenate will become brown in outdoor exposure. Multiple studies demonstrate no excessive corrosion of hardware and fasteners due to contact with the preservative.


Copper Naphthenate's low mammalian toxicity and its EPA registration as a General-use Pesticide make it a preferred choice over traditional oil-borne preservatives like pentachlorophenol and creosote. Copper Naphthenate has been used as a wood preservative for over one-hundred years. Its inclusion in the AWPA preservative standards is assurance Copper Naphthenate is an effective wood preservative you can count on to perform.

Pine posts dip treated with copper naphthenate Pile of copper naphthenate pressure treated utility poles