NW100® is a preservative system based on Alkaline Copper Quaternary compounds for the pressure treatment of wood products. The main active ingredients are copper and quaternary compounds. Copper has long been known to be an effective wood preservative. Copper and quaternary compounds together provide a broad spectrum of long-term protection for wood exposed in exterior applications.

The NW100 preservative system is used in the pressure treatment of wood products in exterior applications both above ground and in ground contact, including:

  • Residential construction such as decks, patios, fencing, siding, plywood, sill plate.
  • Recreational applications such as walkways, boardwalks, landscaping, fresh water docks, and gazebos.
  • Construction and commercial applications such as dimensional lumber, structural timbers, posts, decking.
  • Agriculture and horticulture applications such as fencing, framing, and building poles.

Application Information:

Protect cut ends, drill holes and other field cuts

For NW100 treated timbers and treated wood used in ground contact applications, a brush-on end-cut wood preservative is required at the time of construction on all saw cuts, drill holes and other filed cuts. Two applications of a copper naphthenate based end-cut preservative must be applied to the preserved wood before it is installed. Important: follow the manufacturer’s directions for proper application.

For NW100 treated wood used in above ground applications, such as deck boards, railing, post tops or fence boards, a brush-on end-cut wood preservative or Timber Specialties Cut-N-Seal® product should be applied to all saw cuts, drill holes and other field cuts at the time of construction. Follow the manufacturer’s directions for proper application.

Use corrosion-resistant fasteners

NW100 treated wood products are designed for long-term performance in outdoor applications and, therefore, require high-quality corrosion-resistant nails, screws, fasteners and other hardware.

Warning — Certain metal products (including fasteners, hardware and flashing) may corrode when in direct contact with NW100 pressure treated wood products. To prevent premature corrosion and failure it is important to follow the recommendations of the manufacturers for all metal products.

For interior and exterior applications, use fasteners and hardware that are in compliance with the manufacturer’s recommendations and the building codes for their intended use. As with any good design and construction practices, NW100 treated wood should not be used in applications where trapped moisture or water can occur. Where design and/or actual conditions allow for constant, repetitive, or long periods of wet conditions, only stainless steel fasteners should be used.

Fasteners (and other metal products) for use with NW100 treated wood products include:

  • Hot-Dip Galvanized*
    Fastener and hardware manufacturers have suggested the minimum Hot-Dip Galvanized requirements for use with treated wood should conform to the following ASTM Standards: ASTM-A153 (for Hot-Dip fastener products) and ASTM-A 653 (Coating Designation G-185 for Hot-Dip connector and sheet products).
  • Stainless steel
    Stainless steel fasteners and connectors are required for Permanent Wood Foundations below grade and are recommended for use with treated wood in other severe exterior applications such as swimming pools, salt water exposure, etc. Type 304 and 316 are the recommended grades to use.
  • Other fasteners and hardware as recommended by the manufacturer
    There may be additional products (other than stainless steel or hot-dip galvanized) which are suitable for use with NW100 pressure treated wood. Please consult with the individual fastener or hardware manufacturer for recommendations for use of their products with NW100 treated wood.

* Electroplated galvanized fastener and metal products are typically not accepted by the building codes for use in exterior applications, regardless of the type of wood used.

Aluminum should not be used in direct contact with NW100 treated wood

Spacer materials or other physical barriers are recommended to prevent direct contact of NW100 pressure treated wood and aluminum products. When using NW100 treated wood in close proximity to aluminum products, such as aluminum siding, flashing, furniture, and door and window frames, a 1/4” minimum spacing must be allowed for between the NW100 treated wood and the aluminum products. Polyethylene or nylon spacers can be used to maintain the 1/4” spacing. Another option is to use a polyethylene barrier, with a minimum thickness of 10 mils, between the NW100 treated wood and the aluminum product to prevent direct contact of the wood and the aluminum.

Check appropriate usage on the end tag

Above ground treated material should not be used in ground contact applications as this can adversely affect the performance of the entire project. The appropriate usage is noted on the end tag attached to each piece.

When appearance permits, attach boards bark side up

As a general rule, attach boards bark side up (annual rings arc upward) to reduce cupping; however, the best face should be placed up when a defect of the wood is apparent. Fasten thin boards to thicker boards to maintain structural integrity.

Drill pilot holes

Drill pilot holes especially when nailing or screwing near the edge or end of a board. Pilot holes will help minimize splitting.

Deck board spacing

Should the wood become wet during construction, butt deck boards together. As drying occurs, some shrinkage can be expected. If the wood is dry, allowing for shrinkage is not necessary.

Apply a weather-resistant finish

Any exposed wood, pressure treated or not, should be protected from the weather. Application of a quality clear water repellent or semi-transparent stain, which contains water repellent, will help minimize the cycles of moisture take-up and loss the wood goes through outdoors. First, thoroughly clean your project with a deck cleaning product. Clear water repellent can be immediately applied to your deck or other project. If you choose to use a semi-transparent stain which contains a water repellent, you need to first check that your project is surface dry. Either wait until the surface is dry or immediately apply clear water repellent and wait approximately 8 weeks and then apply your chosen color of semi-transparent stain. Check that the wood is surface dry before applying stain. In all instances follow the manufacturer’s directions when applying water repellents or semitransparent stains which may contain water repellent.

Remove mold with soap and water

Mold growth can and does occur on the surface of many products, including untreated and treated wood, during prolonged surface exposure to excessive moisture conditions. To remove mold from the treated wood surface, wood should be allowed to dry. Typically, mild soap and water can be used to remove remaining surface mold.

Important Information:

  • Do not burn treated wood.
  • Wear a dust mask and goggles when cutting or handling wood.
  • Wear gloves when working with wood.
  • Some preservative may migrate from the treated wood into soil/water or may dislodge from the treated wood surface upon contact with skin. Wash exposed skin areas thoroughly.
  • All sawdust and construction debris should be cleaned up and disposed of after construction.
  • Wash work clothes separately from other household clothing before reuse.
  • Treated wood should not be used where it may come into direct or indirect contact with drinking water, except for uses involving incidental contact such as fresh water docks.
  • Do not use treated wood under circumstances where the preservative may become a component of food, animal feed, or beehives.
  • Do not use treated wood as mulch.
  • Only treated wood that is visibly clean and free of surface residue should be used.
  • Use fasteners, hardware or any metal product as recommended by their manufacturer.
  • Do not use treated wood in direct contact with aluminum.
  • If the wood is to be used in an interior application and becomes wet during construction, it should be allowed to dry before being covered or enclosed.
  • Projects should be designed and installed in accordance with federal, provincial, and local building codes and ordinances governing construction in your area.
  • Residential users may dispose of treated wood scraps and cut offs by ordinary trash collection or burial. Commercial and industrial users of treated wood should dispose of treated wood scraps and cut offs in accordance with local, provincial and federal regulations.
  • Use wood preservatives safely. Always read the label and product information before use.