Pressure treated lumber is treated with Alkaline Copper Quaternary (ACQ), an environmentally friendly water-based preservative that is free of arsenic and chromium. However, ACQ treated lumber is more corrosive to metal, so the right fastener is key to a safe, long lasting deck, fence or other outdoor project.
When nails are exposed to ACQ, a chemical reaction occurs, which accelerates the corrosion rate of the fastener. In addition, the organic components of ACQ attract water, further increasing corrosion on the fastener.
The wood treatment industry recognizes the corrosive nature of ACQ in relation to fastening systems, and recommends hot dipped galvanized or stainless steel nails be used. Hot dipped galvanized nails must meet American Society for Testing and Materials (ASTM) A153 Class D standards and stainless steel nails should be made from grade 304 or 316, to provide maximum corrosion protection. If screws are used they must be rated for ACQ.
Tree Island Steel’s ZincGard® hot dipped galvanized nails are recommended for use in exterior applications and in ACQ pressure treated lumber. Our fasteners meet or exceed all ASTM standards.
For more information on ACQ fasteners, contact the Tree Island Sales Representative in your area.