Joist Width And Hanger Screw Size: Getting The Balance Right

When building a deck or framing a floor, joist hangers are essential for ensuring the structure's stability and security. While nails have traditionally been used to secure joist hangers, screws are becoming increasingly popular due to their improved holding power and durability. However, not all screws are suitable for this purpose, and it is crucial to consider factors such as screw type, length, manufacturer guidelines, building codes, structural integrity, and installation process.

Nails vs. screws for joist hangers

When it comes to joist hangers, the fasteners you use are crucial to ensuring the safety and stability of your structure. While nails are typically used to fasten joist hangers, screws can also be used in certain circumstances.

Nails have stronger shear strength than screws, making them ideal for joist hangers. They are also less expensive and can be easily installed with a hammer or a pneumatic nail gun. However, nails can be more challenging to work with as each swing of the hammer can bump the structure out of alignment. Additionally, nailing into end grain will lessen the nail's holding power.

Screws, on the other hand, are easier to use and can be driven with an impact driver. They pull everything tight as you fasten them, ensuring a secure connection. Screws designed specifically for joist hangers, such as the Simpson SD and SDS connector screws, are strong enough to support joist loads and can be a good alternative to nails. However, standard deck screws, drywall screws, and roofing nails should be avoided as they are vulnerable to breaking under shear stress and do not meet the required shear force for structural support.

When choosing between nails and screws for joist hangers, it is essential to follow the manufacturer's guidelines and use the specified fasteners. This will ensure that your structure meets the required performance and safety standards. Additionally, for exterior installations, it is crucial to use corrosion-resistant finishes such as ZMAX or stainless steel to prevent corrosion.

Galvanized nails for joist hangers

Galvanized nails are a type of fastener used with joist hangers to provide structural support for wood joists in floors, ceilings, and decks. The most common material used for joist hangers is galvanized metal, so galvanized nails are ideal to avoid corrosion. It is important to ensure that the nails are sized correctly and meet the manufacturer's specifications.

For interior framing, thicker nails such as 10d, 12d, or 16d common nails should be used to fasten a joist hanger's face flange to wall ledgers, headers, and beams. For outdoor applications and double joist hangers, 16d galvanized or stainless steel nails are recommended. Hot-dipped galvanized nails are also suitable for both indoor and outdoor use.

When using galvanized nails with joist hangers, it is crucial to follow the manufacturer's guidelines and use the specific types of fasteners specified. This ensures that your floor or deck meets the required performance standards and structural integrity.

Additionally, it is important to fill all the nail holes in the joist hanger to achieve the desired load capacity. Using shorter nails can compromise the strength and safety of the structure. Reusing joist hangers or modifying them by cutting or reshaping should be avoided as it can affect their performance.

In summary, galvanized nails play a crucial role in securing joist hangers and providing long-lasting support for ceilings, roofs, floors, and decks. By using the appropriate nail size, type, and following manufacturer guidelines, you can ensure the safety and stability of your structure.

Deck screws for joist hangers

When building a deck, you may be wondering whether to use deck screws or nails for joist hangers. While structural nails are typically used to fasten joist hangers, you can use screws explicitly made for joist hangers. However, it is important to avoid using any other types of screws, as they cannot support joist loads and are not designed to withstand shear force.

Deck Screw Options

There are a variety of deck screw options available, and it is important to choose the correct type for your specific application. Here are some things to consider:

• Diameter: Deck screws typically have a diameter of either 8 or 10 gauge. For structural wood screws, a 1/4" diameter is commonly used.
• Length: The length of the screw will depend on the specific application. For attaching deck boards to joists, a 2.5" deck screw is commonly used. For brackets such as joist hangers, shorter screws such as 1/4" structural screws in lengths of 1.5" or 2" may be needed.
• Material: For exterior applications, it is important to use screws with a corrosion-resistant coating. Stainless steel screws are ideal for exterior use as they are highly rust-resistant, but they are more expensive. For pressure-treated wood, zinc-coated screws are reliable and affordable, but the copper in the wood will eventually eat away at the zinc.
• Head Style: Flat-head and trim-head deck screws are commonly available. Flat-head screws have a flat top and are used for general applications, while trim-head screws have a trim head and are used for applications where a flush finish is desired.
• Drive Style: Deck screws typically have a Phillips or star drive. Phillips drives are more common and can be used with a standard drill, while star drives provide more torque and reduce cam-out.

Installation Considerations

When installing joist hangers with deck screws, there are a few important considerations to keep in mind:

• Manufacturer Guidelines: It is important to consult the manufacturer's guidelines to ensure you are using the correct type of fasteners for your specific joist hangers. Using the wrong type of fasteners can compromise the integrity of your deck.
• Load Capacity: Deck screws must be able to support the load of the joists. Standard deck screws are vulnerable to breaking when under shear stress, so it is important to use specialty screws that are designed to support joist loads.
• Corrosion Resistance: If you are using galvanized joist hangers, it is important to use galvanized fasteners to avoid corrosion. Using dissimilar metals can lead to corrosion and structural failure.
• Proper Fit: Ensure that the screws you choose fit properly in the joist hanger nail holes. Standard deck screws may be too small and can cause the hanger to fail.

In summary, while it is possible to use deck screws for joist hangers, it is important to choose the correct type of screws and follow the manufacturer's guidelines to ensure a safe and secure installation.

Joist hanger installation mistakes

Joist hangers are essential for building structures that require solid support. They provide critical reinforcement for connecting joists to beams, ensuring weight distribution and maintaining structural integrity. However, improper installation can compromise the stability of the entire structure, leading to costly repairs. Here are some common mistakes to avoid when installing joist hangers:

Mistake 1: Incorrect Joist Hanger Size

Using the wrong size of joist hangers can have significant consequences. If the hangers are too small, they may not be able to support the load adequately, compromising the structural integrity. On the other hand, using oversized hangers can lead to instability and joist movement. It is crucial to refer to the manufacturer's guidelines and, if needed, consult a structural engineer to determine the appropriate hanger size for your project.

Mistake 2: Improper Orientation

Joist hangers have specific load-bearing directions indicated by the manufacturer. Incorrect orientation can result in a weaker connection and reduced load-carrying capacity. Ensure that the joist hangers are facing the correct direction and that the joists are installed with the proper orientation as specified.

Mistake 3: Inadequate Nailing or Fastening

Insufficient or improper nailing or fastening is a critical mistake. Failing to use the recommended number, type, and size of nails or screws can lead to hanger failure, causing the joists to sag or collapse. Always follow the manufacturer's instructions regarding fasteners and ensure that they fully penetrate the hanger and securely attach it to the supporting beam or ledger.

Mistake 4: Lack of Lateral Support

Joist hangers require both vertical and lateral support. Neglecting to provide adequate lateral support can lead to hanger failure over time. Ensure stability by installing blocking between the joists or using additional braces as recommended by building codes or a structural engineer. Lateral support helps prevent excessive movement and maintains the structural integrity of the system.

Mistake 5: Overlooking Moisture Protection

Moisture is detrimental to wood and metal components. Failing to protect the joist hangers from moisture can result in corrosion and weakening of the metal parts. Apply a weather-resistant coating or use galvanized or stainless-steel hangers specifically designed for outdoor or high-moisture environments to maintain their effectiveness and longevity.

Mistake 6: Reusing or Modifying Joist Hangers

It is important to note that joist hangers are designed for one-time use and should not be modified or reused. Reusing or altering the hangers can reduce their load capacity and compromise the strength and reliability of the structure. Always use new hangers and follow the manufacturer's specifications to ensure optimal performance and safety.

Joist hanger fastener options

When installing joist hangers, it is important to select the correct type of fastener. While structural nails are typically used, certain types of screws can also be used.

If you are using screws, they must be explicitly made for joist hangers. Ordinary deck screws, drywall screws, and roofing nails should not be used with joist hangers as they cannot support joist loads and are not designed to withstand shear force.

Simpson SD and SDS connector screws are ideal options. The SD screws are designed for lighter hangers, while the SDS screws are for heavier hangers. Their load values exceed those of typical 10d and 16d common nails.

If you are using nails, hot-dipped galvanized nails are recommended for outdoor use. For indoor use, common nails (not sinker-type) are typically used. 16d and 10d nails are usually recommended for most applications.

It is important to note that the size of the nail matters. Longer nails provide added strength as they bite into the framing members behind the ledger. For standard-type single joist hangers, use 1-1/2-inch joist hanger nails for nailing into the side of the joist. For double hangers, use 8d or 10d nails.

To obtain the full load-bearing capacity of a joist hanger, it is crucial to install the length and size of nail specified by the hanger manufacturer. For interior framing, use thicker nails such as 10d, 12d, or 16d common nails.

Some manufacturers produce specialty nails specifically designed for installing their joist hangers. These nails usually feature thicker shanks than standard nails, allowing them to withstand significant stress. One benefit of using specialty nails is that they pass through joist hanger nail holes without catching, which may be an issue with standard nails.

Frequently asked questions