Joist hangers only meet their performance standards if you install them with the correct fasteners. Manufacturers engineer and test every aspect of their hangers, including acceptable fastener type, because joist hangers play a critical role in supporting ceiling, floor and roof framing members. Although standard deck screws aren't designed to provide the type of strength required by joist hangers, there are several nails and screw-like fasteners perfectly suited for the job. Note that the most reliable way to determine the right fastener for a particular product is to consult the manufacturer's guidelines.
Using Deck Screws on Joist Hangers
Although common deck screws have great holding power, they tend to break more easily than do nails under shear stress. Shear stress is force exerted across the fastener's shank in a back-and-forth direction. Joist hangers are designed to sway gently if they're subjected to shear forces, such as during an earthquake or exceptionally high winds. Regular deck screws often consist of hardened steel, which might snap under such stress. Although specialty screws are available for joist hangers, hanger manufacturers typically advise against using common deck screws for installing their products.
Common Joist Hanger Fasteners
Most joist hanger manufacturers recommend nails for installing joist hangers. The precise type of nail varies according to the project's characteristics and the make and model of the joist hanger. In general, connector manufacturers recommend 16d and 10d framing nails for anchoring joist hangers to headers or walls and shorter nails, called joist hanger nails, for anchoring the joists to the joist hangers. For exterior applications, all fasteners must have a corrosion-resistant coating, such as hot-dip galvanization.
Specialty Joist Hanger Screws
Some construction connector manufacturers produce specially designed screws for use with their joist hanger products. The screws' labeling usually reads "construction connector screw" or "joist hanger screw." Joist hanger screws typically have thicker shanks or alternative thread designs that allow them to withstand the type of stress that would snap common deck screws. Additionally, whereas common screws sometimes don't fit through joist hanger nail holes, product-specific screws are sure to slide through openings without catching.
Fastening Related Connectors
If you're working with joist hangers, you're likely to encounter a variety of construction connectors during your project, including tie straps, post base brackets and post cap saddles. Screws are suitable and often recommended for many of these related connectors, particularly post base brackets and post cap saddles. Before resigning yourself to nailing the entire project, consult your connector manufacturer's guidelines to determine if screws are suitable for a portion of your project.