The Simpson Light Tension Tie LTTI31 from Simpson is an 18-gauge steel connector engineered to resist tension loads when attaching wood to concrete or masonry walls. Designed primarily for horizontal purlin applications, it also supports vertical holdown use, making it a versatile solution across a range of structural connections. The LTTI31 is built specifically for wood-chord open-web truss attachments and includes a built-in load transfer plate washer that delivers increased load performance at the connection point. The low-profile design and multiple nailing options make it a practical choice for contractors working with purlin, rafter, and truss framing systems.

Key Features

• Multiple nailing patterns to accommodate different purlin, rafter, and truss types - gives installers the flexibility to work across a variety of framing configurations without needing a different connector for each application.
• Built-in load transfer plate washer - increases performance at the connection point on wood-chord open-web truss attachments, delivering stronger, more reliable load transfer where it matters most.
• Low-profile seat design - minimizes the visibility of the tie once installed, keeping finished assemblies clean and unobtrusive.
• Tested with different anchor bolt diameters - ensures code-required performance across varying substrates, so the right anchor solution is always available for the specific application.
• G90 galvanized coating - provides extra corrosion resistance to help the connector hold up in conditions where moisture and the elements are a concern.
• Compatible with vertical installation on a minimum 2x6 stud with nails - expands the range of installation scenarios without requiring specialized framing dimensions beyond standard lumber sizing.

Why This Product

• Purpose-built for wood-chord open-web truss connections - the LTTI31 is specifically engineered for this demanding application, with a built-in load transfer plate washer that standard light tension ties lack, meaning contractors get optimized performance without field modifications.
• Dual-purpose versatility - a single connector handles both horizontal purlin attachments and vertical holdown applications, reducing the number of different SKUs a crew needs to carry on the job and simplifying procurement for mixed-application projects.
• Tested across anchor bolt diameters and substrates - including unreinforced concrete masonry with 3/4 in. post-installed anchor bolts, the LTTI31 meets real-world code requirements across the substrate types most commonly encountered in structural and commercial framing work.
• Made in the United States from 18-gauge steel with a G90 galvanized finish - combines structural-grade material thickness with corrosion-resistant protection, supporting long-term performance in both interior and exposed structural environments.

Specifications

• MPN: LTTI31
• Brand: Simpson Strong-Tie
• Length: 31 in.
• Width: 3-3/4 in.
• Gauge: 18
• Coating: Zinc Galvanized, G90
• Finish: Zinc Galvanized, G90
• Country of Origin: United States

Approved Applications

• Horizontal purlin applications for resisting tension loads
• Vertical holdown applications
• Wood-chord open-web truss attachments
• Attaching wood to concrete or masonry walls
• Applications with unreinforced concrete masonry using 3/4 in. post-installed anchor bolts

Install With (sold separately)

• Install with (1) 5/8 in. anchor bolt and (18) 0.148 in. x 1-1/2 in. nails

Frequently Asked Questions

What is the Simpson Strong-Tie LTTI31 designed for?

The LTTI31 is a light tension tie designed for horizontal purlin applications and may also be used for vertical holdown applications. It is specifically built for wood-chord open-web truss attachments and is used to resist tension loads when attaching wood to concrete or masonry walls.

What hardware is required to install the LTTI31?

The LTTI31 should be installed with (1) 5/8 in. anchor bolt and (18) 0.148 in. x 1-1/2 in. nails. It may be installed vertically on a minimum 2x6 stud with nails.

What gauge steel is used, and what corrosion protection does the LTTI31 have?

The LTTI31 is made from 18-gauge steel and features a Zinc Galvanized G90 coating for extra corrosion resistance, making it suitable for applications where durability against the elements is important.

What anchor bolt size is commonly used with the LTTI31 in unreinforced concrete masonry applications?

For LTT tension tie applications with unreinforced concrete masonry, 3/4 in. post-installed anchor bolts are commonly used. The LTTI31 has been tested with different anchor bolt diameters to meet code-required applications based on substrate.