What are Joist Hangers and More FAQ

What are Joist Hangers?

Joist hangers are essential structural connectors used to anchor joists to beams, walls, and ledgers securely. Designed to provide superior load-bearing strength, they help distribute weight evenly and prevent wood members from shifting over time. Joist hangers are widely used in deck construction, flooring systems, and roof framing, ensuring a stable and long-lasting structure. Without joist hangers, wood framing connections would rely solely on toe-nailing, which is less reliable and weaker under heavy loads.

What Types of Joist Hangers are There?

Joist hangers come in many styles and are intended for a wide variety of joists, depending on the construction project. In this case, we're referring to the style as its designed features - like face-mount, top-flange, or concealed, while the joist type could be solid-sawn or I-joists, and more. And keep in mind, some joist hangers can be considered more than one style, like face-mount and concealed. Below we break them down further:

Styles of Joist Hangers:

Standard Joist Hangers

The most commonly used joist hangers, standard hangers feature a U-shaped design with pre-drilled nail or screw holes for quick and secure fastening. They are used in general framing applications, such as decks and floor joists.

• Example: U/LU/LUC Joist Hangers

Face-Mount Joist Hangers

Designed for installation on the face of a beam or ledger board, these hangers provide a flush fit and superior structural support. They are widely used in deck construction and wooden floor framing.

• Example: LUS Joist Hangers or HU Heavy Joist Hangers

Top-Flange Joist Hangers

Instead of being mounted on the side of a beam, top-flange hangers rest on top of a supporting structure, making them ideal for concealed connections in trusses and multi-story buildings.

• Example: BA/JB/LB Top-Flange Joist Hangers

Concealed-Flange Joist Hangers

Featuring hidden fastening points, concealed-flange hangers offer a cleaner, more aesthetic look while maintaining the same strength as traditional face-mount options. These are commonly used in decorative projects.

• Example: Concealed Joist Hangers

Double-Shear Joist Hangers

These hangers allow nails to be installed at an angle through the joist into the supporting beam, increasing load capacity and shear strength. Double-shear hangers are perfect for heavy-duty framing and commercial applications. As far as naming application, whenever you see the 'S' in the name, like LUS or HUS, that refers to the hanger having this feature.

• Example: LUS Joist Hangers or HUS Joist Hangers

Sloped/Skewed Joist Hangers

For angled connections, sloped or skewed joist hangers provide an adjustable mounting solution. They are used in stair stringers, hip roofs, and custom framing projects where joists are not perpendicular to beams.

• Example: SUR/SUL Sloped/Skewed Joist Hangers

Heavy-Duty Joist Hangers

Designed for extreme load-bearing applications, heavy-duty hangers are reinforced with thicker steel and larger nail holes, making them ideal for commercial and industrial construction.

• Example: HUC/HUCQ Heavy Joist Hangers

Adjustable Joist Hangers

These versatile hangers can accommodate different joist sizes, making them ideal for irregular framing situations. They are used in retrofitting projects and repairs where exact measurements are not always standard.

• Example: LSSR/LSSJ Adjustable Rafter Hangers

Masonry Joist Hangers

Designed to be anchored into concrete or brick walls, masonry joist hangers feature a built-in flange that allows them to be embedded into mortar joints or bolted into the surface.

• Example: HU Masonry Hangers

Materials and Finishes of Joist Hangers

• Galvanized Steel: Most joist hangers are made from galvanized steel to provide corrosion resistance, making them suitable for indoor and outdoor use.
• Stainless Steel: For maximum durability, especially in coastal or high-humidity environments, stainless steel joist hangers resist rust and corrosion better than galvanized options.
• Powder-Coated & Painted Options: Aesthetic joist hangers with powder-coating or paint finishes add durability and visual appeal, making them popular for exposed wood structures.
• ZMAX & Hot-Dip Galvanized Coatings: ZMAX-coated hangers provide additional corrosion resistance for use in pressure-treated lumber applications, while hot-dip galvanized hangers are ideal for extreme weather conditions.

How to Choose the Right Joist Hanger

• Load Capacity Considerations: Joist hangers are rated for different weight capacities based on their material, gauge thickness, and installation method.
• Wood vs. Steel Joists: While wood joist hangers are the most common, some applications require steel hangers to support metal joists, particularly in industrial construction.
• Compatibility with Treated Lumber: Some wood treatments, such as ACQ and CA-treated lumber, can corrode standard joist hangers. Using ZMAX-coated or stainless steel hangers is recommended for longevity.
• Building Code Compliance: Many local building codes specify which joist hangers should be used based on the structure’s load requirements and environmental exposure.

If you need any help selecting a joist hanger, be sure to contact us - or use Simpson's Connector Selector Tool.

How to Install Joist Hangers

Tools & Fasteners Required

• Nails: Designed specifically for joist hangers, structural nails provide high shear strength.
• Screws: Only use manufacturer-approved structural screws, as standard screws lack the necessary strength.
• Hurricane Clips & Reinforcement Plates: Optional accessories for additional support in high-wind zones.

Common Installation Mistakes

• Overdriving nails: Can weaken the connection and damage the wood.
• Using incorrect fasteners: Non-structural screws or framing nails reduce safety.
• Misalignment: Joist hangers must be properly centered and secured to distribute weight evenly.

Common Joist Hanger Applications

• Deck Construction: Joist hangers provide critical support for deck framing, ensuring the joists stay securely fastened to the ledger board.
  • For more help on deck construction, see our blog on How to Install Deck Joist Hangers
• Floor Framing: Used in residential and commercial flooring, joist hangers help create level and stable subfloor systems.
• Roof Trusses & Rafters: Joist hangers secure rafters and ceiling joists, preventing movement and ensuring load distribution.
• Bridges & Outdoor Structures: Heavy-duty hangers are commonly used in pedestrian bridges, gazebos, and pergolas.
• Masonry Attachments: Specialty hangers allow joists to be attached to concrete walls or brick surfaces using anchor bolts or embedded mounting brackets.

Strength & Testing Standards

• Load Ratings & Engineering Specifications: Joist hangers undergo rigorous testing to meet industry standards, including ASTM and ICC-ES approval.
• Seismic & Wind-Resistant Options: In earthquake-prone areas, joist hangers must meet seismic load resistance codes. High-wind areas require reinforced models with additional anchoring points.
• Fire-Rated Hangers: Some applications require fire-rated joist hangers, which are designed to maintain strength under extreme heat conditions.

8. Maintenance & Longevity

Routine Inspection

Regularly check joist hangers for rust, loose fasteners, or wood rot that could compromise strength.

Preventing Corrosion

For outdoor applications, ensure proper drainage and ventilation to minimize moisture buildup around hangers.

Replacing Damaged Hangers

If a joist hanger shows signs of deterioration, replace it immediately to prevent structural failure.

Further Questions on Joist Hangers

Understanding joist hangers and their role in structural framing helps DIYers and professionals ensure stronger, longer-lasting connections. Whether you're building a deck, framing a floor, or working with engineered wood, having the right knowledge about joist hangers can improve safety, efficiency, and project success.