Choosing Fasteners for Use with Micronized Copper Treated Products
Micronized copper treated products offer many benefits including significantly improved corrosion performance. YellaWood® brand pressure treated pine with micronized copper preservatives exhibits corrosion rates on metal products similar to CCA pressure treated wood, and untreated wood.
For interior or 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, micronized copper 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.
For exterior applications
The following recommendations should be followed when choosing connectors, joist hangers, fasteners and other hardware that are placed in direct contact with exterior applications of micronized copper treated wood:Fasteners (nails, screws, etc.)
- Hot-Dip Galvanized ASTM - A 153 (1 oz./ft²)
- Epoxy Coated Carbon Steel (Zinc plated) AC-257
- Stainless Steel 304, 305 (Alloy Group 1) or 316 (Marine Grade)
- Compliant with ASTM - A 653 G90 (0.90 oz./ft²)
The effects of other building materials within a given assembly, along with environmental factors, should also be considered when selecting the appropriate hardware and fasteners to use for a given project containing treated wood.
Stainless Steel fasteners and hardware 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, 305 and 316 are recommended grades to use.
Aluminum building products may be placed in direct contact with YellaWood® brand products with micronized copper preservatives used for interior uses and above ground exterior applications such as decks, fencing, and landscaping projects. Examples of aluminum products include siding, roofing, gutters, door and window trim, flashing, nails, fasteners and other hardware connectors. However, direct contact of micronized copper treated products and aluminum building products should be limited to code-compliant construction applications that provide proper water drainage and do not allow the wood to be exposed to, or remain in contact with a continual moisture source, standing water or water immersion. In addition, micronized copper treated wood should not be encased, sealed, or wrapped with aluminum products where trapped moisture or water can occur so as to avoid pitting or other unwanted results.
We recommend you contact the aluminum building products manufacturer for its recommendations regarding use of its aluminum products in contact with micronized copper treated wood in ground contact applications or when exposed to salt water, brackish water, or chlorinated water, such as swimming pools or hot tubs.
Also check with the aluminum building products manufacturer regarding compatibility with other chemicals and cleaning agents. Contact Koppers Performance Chemicals for further information on aluminum contact use in commercial, industrial, and specialty applications such as boat construction.