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DTT Deck Post Connector

DTT

DTT tension ties are safe, cost-effective connectors designed to meet or exceed code requirements for deck construction. These versatile DTT connectors are also load-rated as a holdown for light-duty shearwalls and braced wall panel applications.

For new construction or to make an existing current deck code-compliant, the DTT1Z can be used as a tension-tie to satisfy the 2015 IRC provision for a 750 lbs. lateral load connection to the house at four locations per deck. This new code detail permits the lateral connection from the deck joists to be made to top plates, studs, or headers within the supporting structure, which eliminates the need to access to the floor joists inside the home. The DTT1Z connector is available individually or in a kit of 4 along with 4 Strong-Drive® SDWH Timber-Hex HDG screws and 24 Strong-Drive® SD Connector screws.

The new DTT1Z fastens to the narrow or wide face of a single 2x with Simpson Strong-Tie® Strong-Drive® SD Connector screws or nails and accepts a 3/8" machine bolt, anchor bolt, or lag screw (washer required) or can be installed with the new Strong-Drive SDWH Timber-Hex HDG screw with an integral washer. The DTT2 fastens easily to the wide face of a single or double 2x using Simpson Strong-Tie Strong-Drive SDS Heavy-Duty Connector screws (included) and accepts a ½" machine bolt or anchor bolt.

The DTT2 can be used to satisfy the IRC provision for a 1,500 lbs. lateral load connection at two locations per deck. Additionally, the DTT2 has been tested and evaluated in deck guardrail post applications to resist the code-specified lateral forces at the top of railing assemblies. The DTT2 is also available with longer 2½" Strong-Drive SDS Heavy-Duty Connector screws (model DTT2Z-SDS2.5) to achieve higher loads when needed.

Material

14 gauge

Finish

DTT1Z/DTT2Z—ZMAX® coating; DTT2SS—Stainless steel. See Corrosion Information.

Installation

  • Use all specified fasteners. See General Notes.
  • A standard cut washer (refer to General Notes) must be installed between the nut and the seat.
  • Simpson Strong-Tie Strong-Drive SDS Heavy-Duty Connector screws install best with a low-speed high-torque drill with a 3/8" hex head driver.
  • Strong-Drive SD Connector screws install with a 1/4" hex head driver.
  • Strong-Drive SDWH Timber-Hex HDG screws install with a 1/2" hex head driver.
  • For Shearwall Installation, see HDU/DTT.

Related Literature

Load Tables

    These products are available with additional corrosion protection. Additional products on this page may also be available with this option, check with Simpson Strong-Tie for details.

  1. The allowable loads have been increased 60% for wind or earthquake loading with no further increase allowed.
  2. DTT1Z installations with allowable loads below 750 lbs. do not satisfy the 2015 IRC requirements for deck-to-house lateral load connections.
  3. The Strong-Drive® SDWH Timber-Hex HDG screw with a minimum of 3" of thread penetration into dry lumber has an allowable withdrawal load (160) of 1380 lbs. into SP, 1225 lbs. into DF and 1020 lbs. into SPF/HF.
  4. Load values are valid if the product is flush with the end of the framing member or installed away from the end.
  5. The guardrail post illustration above addresses an outward force on the guardrail. An additional DTT2Z can be added at the lower bolt to address an inward force.
  6. A 3/8" HDG round washer is required when using a lag screw.

Code Reports

Part IAPMO UES ER ICC-ES ESR City of Los Angeles State of Florida
DTT1Z ER-102 ER-130
DTT2SS No code listing. Please contact us for test data.
DTT2Z ESR-2330 ESR-2523 RR25720 FL10441
DTT2Z-SDS2.5 ESR-2330 ESR-2523 RR25720 FL10441

ESR-2523 is an Index of many of Simpson Strong-Tie Stamped and Welded Cold-formed Steel Products for Wood or Cold-formed Steel Construction

Drawings

Part Orthographic Perspective
DTT1Z
DTT1Z bottom view
DWG DXF
DTT1Z front view
DWG DXF
DTT1Z left view
DWG DXF
DTT1Z right view
DWG DXF
DTT1Z top view
DWG DXF
DTT1Z
DWG DXF
DTT2None None
DTT2Z
DTT2Z
DWGDXF
DTT2Z front view
DWG DXF
DTT2Z left view
DWG DXF
DTT2Z right view
DWG DXF
DTT2Z top view
DWG DXF
High Wind-Resistant Construction D61: Stemwall/Crawlspace
DWG DXF
DTT2Z
DWG DXF
DTT2Z installed
DWG DXF