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Fastener Information
Fasteners (and other metal products) for use with CA-B pressure-treated wood products
• Hot-Dip Galvanized*
Fastener and hardware manufacturers have suggested the minimum Hot-Dip galvanized
requirements for use with CA-B 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, saltwater 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 CA-B preserved wood. Please consult with the individual fastener or hardware manufacturer for recommendations for use of their products with CA-B preserved wood.
• Dry Use Applications
When CA-B preserved wood is used for interior applications with continuous dry conditions, where the wood in service will remain below 19% equilibrium moisture content, the performance of fasteners, hardware and other metal products in contact with the treated wood should be similar to that experienced with untreated wood.
• Aluminum should not be used in direct contact with CA-B preserved wood
Spacer materials or other physical barriers are recommended to prevent direct contact of
CA-B preserved wood and aluminum products.
These fastener recommendations are comparable to fastener recommendations from other wood preservative manufacturers of Copper Azole and ACQ.
*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.
2006 International Residential Code - Fastener Statement - section R319.3
Fasteners for pressure-preservative and fire-retardant treated wood shall be of hot-dip zinc-coated galvanized steel, stainless steel, silicon bronze or copper. The
coating weights for zinc-coated fasteners shall be in accordance with ASTM-A153.
Exceptions:
1. One-half-inch (12.7 mm) diameter or larger steel bolts.
2. Fasteners other than nails and timber rivets shall be permitted to be of
mechanically deposited zinc-coated steel with coating weights in accordance
with ASTM-B695, Class 55, minimum. |
