Can I Use Deck Screws on Joist Hangers?

While deck screws can technically be used on joist hangers, it's not recommended and may compromise the integrity of the structure. Joist hangers are designed to be used with nails specifically made for this purpose.

Here are the reasons why you shouldn't use deck screws on joist hangers:

1. Lack of Holding Power: Joist hanger nails have a unique "L" shape that provides superior holding power compared to deck screws. The shape of these nails allows them to wedge securely into the wood, preventing the joist from pulling away from the hanger under stress. Deck screws, on the other hand, have a straight shank and rely solely on thread engagement for holding power, which is less effective in this application.

2. Potential for Over-Driving: Deck screws are more prone to over-driving, which can damage the joist and weaken the overall connection. Over-driving occurs when the screw is driven in too deep, causing the head to sink below the surface of the wood. This can compromise the structural integrity of the connection, making it susceptible to failure. Joist hanger nails are less likely to be over-driven because they are designed to be flush with the surface of the wood.

3. Increased Corrosion: Deck screws are typically coated with a layer of zinc to resist corrosion, but this coating may not be sufficient for the exposed environment where joist hangers are located. The outdoor elements, such as moisture and chemicals from treated lumber, can accelerate the corrosion process, causing deck screws to rust and deteriorate over time. Joist hanger nails, on the other hand, are hot-dipped galvanized, which provides superior corrosion resistance and makes them more suitable for outdoor use.

4. Incorrect Code Compliance: Using deck screws on joist hangers may not meet code requirements in some areas. Building codes often specify the type of fasteners that should be used for structural connections, and joist hanger nails are the recommended choice for this application. Using deck screws could potentially lead to code violations and compromise the safety of your structure.

5. Compromised Structural Integrity: Joist hanger connections play a crucial role in transferring loads from the joists to the supporting structure, ensuring the stability of the deck. Using the wrong type of fasteners, such as deck screws, can weaken this connection and increase the risk of structural failure.

Given these factors, it's strongly advised to use joist hanger nails specifically designed for this purpose to ensure a safe and code-compliant installation.