General Contractor Practice Exam

What type of nail is not recommended for use in framing below grade with pressure-treated wood?

1. Hot tipped zinc coated galvanized

2. Stainless steel

3. Bright common nails

4. Coated deck screws

The correct answer is: Hot tipped zinc coated galvanized

Hot dipped zinc-coated galvanized nails may not be recommended for use in framing below grade with pressure-treated wood because the chemical preservatives used in pressure-treated lumber can lead to corrosion of these nails over time. While hot-dipped galvanized nails are generally designed to withstand exposure to moisture and some degree of corrosive elements, they do not have the same level of corrosion resistance as stainless steel. Pressure-treated wood often contains copper-based preservatives, which can induce accelerated corrosion on certain metal fasteners, particularly those that are not rated for such environments. In contrast, stainless steel fasteners provide excellent corrosion resistance, making them a better choice for damp or moist conditions, such as framing below grade. Coated deck screws are designed for exterior use and can also be effective, but they may not be as robust as stainless steel in terms of long-term corrosion resistance. Bright common nails are also not suitable because they lack any form of protective coating, making them highly susceptible to rusting when exposed to moisture or the chemicals in pressure-treated wood. Understanding the corrosive effects of pressure-treated wood on various types of nails helps contractors make informed decisions about fasteners used for construction projects, ensuring durability and structural integrity.