Building code authorities specify nailing requirements in documents called "nailing schedules." Nailing schedules rarely differentiate between basement walls and above-grade walls. However, basement walls significantly differ from above-grade walls in other aspects. As basement floors are generally concrete, attaching walls to basement floors requires heavy-duty anchors. Because basements are prone to flooding and seepage, building codes require special measures to prevent rot and moisture damage where wood framing contacts basement floors. Along with a review of stud-wall nailing requirements, an overview of common basement framing practices prepares you to successfully construct basement walls and adhere to building codes.
Nail Types and Sizes
Although specific requirements vary according to local building codes, most codes allow either common framing nails or vinyl-coated "sinkers" for basement framing. Fastener manufacturers and carpenters use archaic terminology to identify nail sizes. Following a numeral, a lowercase "d" represents the word "penny," which refers to an outdated system of determining price. To frame standard stud walls, carpenters may use a combination 16d, 10d and 8d nails. Common 16d framing nails, called "commons," measure roughly .162 of an inch in diameter and 3 1/2 inches in length. Vinyl-coated 16d sinkers measure roughly .148 of an inch around and 3 1/2 inches long. Common and vinyl-coated 10d nails typically measure 3 inches long and .148 of an inch around. Common and vinyl-coated 8d nails measure 2 1/2 inches long and .131 of an inch around.
Requirements by Connection Type
Nail size requirements vary according to the location of the connection or the components that the nails connect. For example, to end-nail through top plates into studs, building codes typically require two 16d nails. To connect studs to bottom plates from above, a technique called "toe-nailing," building codes allow two 16d nails or three 8d nails. Codes generally allow 10d nails for laminating or "face nailing" adjacent studs. Although 16d nails are allowed for nearly all types of connections, smaller nails are more convenient or suitable under particular circumstances. Ultimately, builders must become familiar with local building codes before framing basement additions.
Basement Floor Contact Requirements
Building authorities generally require basement walls that rest on concrete surfaces to have a bottom plate constructed of rot- and pest-resistant lumber called "treated" lumber. Manufacturers use several chemical preservatives to "treat" lumber. Following treatment, many wood products exhibit a distinctive green hue. Whether optional or required by code, treated lumber protects basement framing from the harmful affects of flooding and seepage.
Anchoring Bottom Plates to Concrete Floors
Carpenters use special concrete fasteners to anchor bottom plates to concrete basement floors. Common concrete fasteners include wedge anchors, concrete screws and powder-driven nails. To install wedge anchors and concrete screws, carpenters drill starter holes and drive the fasteners through lumber into the concrete floor. Powder-driven nailing tools, also called "powder-actuated" tools, use explosive gunpowder to drive nails through both lumber and concrete without pre-drilling.