Fasteners (and other metal products) for use with wood products treated with ACQ preservatives include:
- Hot-Dip Galvanized*
Fastener, hardware and other metal products 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 A653 (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, hardware and other metal products as recommended by the manufacturer
There may be additional products (other than stainless steel or hot-dip galvanized), which are suitable for use with ACQ treated wood. Please consult with the individual fastener or hardware manufacturer for recommendations for use of their products with ACQ treated wood.
- Aluminum should not be used in direct contact with wood products treated with ACQ preservatives
Spacer materials or other physical barriers are recommended to prevent direct contact of wood treated with ACQ and aluminum building products. When using products treated with ACQ in close proximity to aluminum, such as aluminum siding, flashing, furniture, and door and window frames, a 1/4" minimum spacing must be allowed for between the treated wood and the aluminum products. Another option is to use a polyethylene barrier, with a minimum thickness of 10 mils, between the ACQ treated wood and the aluminum product to prevent direct contact of the wood and the aluminum. Certain adhesives add extra holding power. Apply adhesives in accordance with manufacturer's directions.
* 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.
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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.
Use an endcoat preservative.
Brush-on endcoat wood preservative is recommended on all saw cuts and in drill holes during construction of wood projects. Also apply on areas where moisture can collect. Always follow manufacturer's recommendations.
The moisture content of pressure treated wood products can vary. If the moisture
content of the treated wood is high, deck boards should be butted together because spaces will occur between the boards as they lose moisture content in service. If the wood has been kiln dried after treatment or otherwise has low moisture content, a 1/8” spacing is recommended.
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. For
more information visit www.epa.gov.
The ACQ preservatives penetrate deeply into and will remain in the wood for a long period of time. 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.
● Consult the end tag to determine which preservative or preservative system was used in the treatment of that particular product.
Warning-Certain metal products (including fasteners, hardware and flashing) may corrode when in direct contact with wood products treated with ACQ preservatives. To prevent premature corrosion and failure, consult the end tag to determine which preservative or preservative treatment was used and follow the metal products manufacturers’ recommendations (including Fastener Information Sheets, if any) as they relate to the specific preservative or preservative system indicated on the end tag.
● Warning-Do not use wood treated with ACQ (Alkaline Copper Quaternary) in direct contact with aluminum.
● Use fasteners and other hardware which are in compliance with building codes for the intended use.
● Do not burn preserved wood.
● Wear a dust mask and goggles when cutting or sanding 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.
● Preserved 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 and bridges.
● Do not use preserved wood under circumstances where the preservative may become a component of food, animal feed or beehives.
● Do not use preserved wood as mulch.
● Only preserved wood that is visibly clean and free of surface residue should be used.
● 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.
● If you desire to apply a paint, stain, clear water repellant or other finish to your preservative treated wood, we recommend following the manufacturer's instructions and label of the finishing product. Before you start, we recommend you apply the finishing product to a small exposed test area before finishing the entire project to insure it provides the intended result before proceeding.
● Projects should be designed and installed in accordance with federal, state and local building codes and ordinances governing the construction in your area, and in accordance with the National Design Specifications (NDS) and the Wood Handbook.
● 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. For more information visit www.epa.gov.
● Disposal Recommendations: Preserved wood may be disposed of in landfills or burned in commercial or industrial incinerators or boilers in accordance with federal, state and local regulations.