The Simpson DTT1Z-KT Deck Tension Tie Kit from Simpson Strong-Tie is a complete, code-compliant connector solution engineered to secure a deck ledger connection to a home - and to tie guardrail posts into deck framing - without requiring access to interior floor joists. Built from 14-gauge steel with a ZMAX galvanized finish, these tension ties are designed for both new deck construction and retrofitting an existing deck to current code standards, delivering a stronger and safer connection than nails, lag screws, or bolts. Each kit ships with all the fasteners needed for a single installation, so there is nothing extra to source before the job begins.

Key Features

• No interior access required - installs without opening up interior floors or walls, making it a far less invasive option for new builds and retrofit projects alike
• Fastens to the narrow or wide face of a single 2x member - gives installers layout flexibility and simplifies placement in tight or awkward framing conditions
• Ties guardrail posts directly into deck framing - reinforces a connection point that is frequently under-built, improving the structural integrity of the entire deck assembly
• Stronger and safer than nails, lag screws, or bolts - engineered specifically for deck tension applications, providing a more reliable lateral load connection at the ledger
• Ties the deck into the house for a stronger ledger connection - addresses one of the most common causes of deck failure, helping the structure meet or exceed current code requirements
• 14-gauge steel with ZMAX galvanization - the heavy-duty coating provides added corrosion resistance in exterior and treated-wood applications, extending the service life of the connector
• Kit includes connectors and all required fasteners - each kit contains (4) DTT1Z connectors, (4) Strong-Drive SDWH Timber-Hex HDG screws, and (26) #9 x 1-1/2 in. Strong-Drive SD Connector screws, so the hardware arrives ready to install
• Also load rated as a holdown for light-duty shearwall and braced wall panel applications - extends the product's value beyond deck work, making it a versatile connector for multiple structural uses on a single job site

Why This Product

• A less invasive deck attachment method that still meets code - because the DTT1Z installs from the exterior without requiring interior floor joist access, it dramatically reduces labor and disruption on both new construction and existing-deck retrofit projects, while still delivering a connection that meets or exceeds code requirements
• Everything for one complete installation, in one kit - rather than sourcing connectors and fasteners separately, this kit bundles (4) DTT1Z connectors with their corresponding Strong-Drive SD Connector screws and SDWH Timber-Hex HDG screws, eliminating guesswork and extra trips to the supply house
• Corrosion-resistant construction built for the long haul - the ZMAX galvanized finish on 14-gauge steel is specifically suited for exterior environments and direct contact with treated lumber, helping the connectors hold up through years of weather exposure without premature degradation
• Dual-purpose connector adds job-site versatility - in addition to serving as a deck tension tie for ledger and guardrail post connections, the DTT1Z is also load rated as a holdown for light-duty shearwall and braced wall panel applications, giving contractors a single connector that covers multiple code-required connection points

Specifications

• MPN: DTT1Z-KT
• Brand: Simpson Strong-Tie
• Coating / Finish: ZMAX
• Gauge: 14
• Member Size: Single or double 2x
• Depth: 1-1/2 in.
• Height: 7-1/8 in.
• Seat Depth: 1-7/16 in.
• Centerline: 3/4 in.
• Screw Offset: 3/16 in.
• Country of Origin: United States

Approved Applications

• Lateral load deck-to-house ledger connection for new deck construction
• Retrofitting an existing deck to current code standards
• Tying guardrail posts into deck framing
• Light-duty shearwall holdown applications
• Braced wall panel applications

What's Included

Each kit contains (4) DTT1Z connectors, (4) Strong-Drive SDWH Timber-Hex HDG screws (SDWH27800G), and (26) #9 x 1-1/2 in. Strong-Drive SD Connector screws - providing a complete hardware solution for one code-compliant deck installation.

Downloads and Resources

• See Load Tables & SPECS : Specifications

Frequently Asked Questions

Do I need to open up interior walls or floors to install the DTT1Z deck tension tie?

No. The DTT1Z is specifically designed to provide secure deck attachments without requiring access to interior floor joists, making it a less invasive approach for both new installations and retrofits.

What fasteners are compatible with the DTT1Z, and are they included in this kit?

The DTT1Z fastens to the narrow or wide face of a single 2x with Simpson Strong-Tie Strong-Drive SD Connector screws (SD9112) or nails, and accepts a 3/8 in. machine bolt, anchor bolt, or lag screw (washer required). It can also be installed with the Strong-Drive SDWH Timber-Hex HDG screw (SDWH27800G) with an integral washer. This kit includes (4) Strong-Drive SDWH Timber-Hex HDG screws (SDWH27800G) and (26) #9 x 1-1/2 in. Strong-Drive SD Connector screws, so no additional hardware purchases are required for a standard installation.

Why is ZMAX galvanization important for deck tension ties?

ZMAX galvanization provides added corrosion resistance specifically suited for exterior and treated-wood applications. Because deck framing is constantly exposed to moisture and pressure-treated lumber, ZMAX coating helps ensure the connector maintains its structural integrity over time in these demanding environments.

Can the DTT1Z be used for applications other than deck construction?

Yes. In addition to serving as a deck tension tie, the DTT1Z connectors are also load rated as a holdown for light-duty shearwall and braced wall panel applications, offering versatility beyond standard deck ledger connections.