Simpson Strong‑Tie offers a wide variety of holdown devices designed and tested to address many applications and load demands. The DTT2 Tension Tie & Holdown is designed for lighter‑duty holdown applications on single or double studs. It can also be utilised in horizontal applications as a tension tie to provide balustrade or similar support. It installs easily with the Strong‑Drive^® SDS Heavy‑Duty Connector screws (included). The DTT2 is ideal for retrofit or new construction projects. They provide high-strength, post-pour, concrete-to-steel connections.

The DTT2 is a safe, cost-effective way to attach deck-railing posts to the deck framing for stronger, safer railings. Because the post is tied back into the deck joists, rather than to the boundary joist alone, the connection is stronger than typical through-bolt installations.

Please check the Corrosion Information to see if it is suitable for your application.

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Carbon Steel 2mm thick

ZMAX^® Galvanised

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Stronger and safer than typical through-bolt installations for deck post connections
Engineered swages for extra strength and to minimise deflections
Suitable for lighter duty holdown applications on single or double studs
Ties the guardrail post into deck framing for a stronger, safer connection
The DTT2 is ideal for lateral-load connections between the deck and house
Helps prevent a common type of deck failure
15mm diameter anchor hole can accommodate Simpson Strong-Tie M12 Titen HD Screw Anchor or any M14 threaded rods
Installs easily with Strong-Drive^® SDS screws (included)

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\r\n\t\t\t\t Model No. \r\n\t\t\t	\r\n\t\t\t\t Dimensions (mm) \r\n\t\t\t	\r\n\t\t\t\t Fasteners \r\n\t\t\t	\r\n\t\t\t\t Minimum Timber Member Size (Depth x Breadth, mm) \r\n\t\t\t	\r\n\t\t\t\t Design Tension Capacity (kN) \r\n\t\t\t\t\tk1 = 1.14 \r\n\t\t\t
\r\n\t\t\t\t Strap \r\n\t\t\t\t\tThickness \r\n\t\t\t	\r\n\t\t\t\t W \r\n\t\t\t	\r\n\t\t\t\t H \r\n\t\t\t	\r\n\t\t\t\t B \r\n\t\t\t	\r\n\t\t\t\t CL \r\n\t\t\t	\r\n\t\t\t\t Anchor Hole Dia (mm) \r\n\t\t\t	\r\n\t\t\t\t Post (Nails: No. - Length x Dia., Screws: No. - Dia. x Length, mm) \r\n\t\t\t
\r\n\t\t\t\t DTT2Z \r\n\t\t\t	\r\n\t\t\t\t 2 \r\n\t\t\t	\r\n\t\t\t\t 85 \r\n\t\t\t	\r\n\t\t\t\t 175 \r\n\t\t\t	\r\n\t\t\t\t 40 \r\n\t\t\t	\r\n\t\t\t\t 21 \r\n\t\t\t	\r\n\t\t\t\t 12 \r\n\t\t\t	\r\n\t\t\t\t 8 – SDS6.4 x 38 \r\n\t\t\t	\r\n\t\t\t\t 90 x 38 \r\n\t\t\t	\r\n\t\t\t\t 9.3 \r\n\t\t\t

\r\n\r\n

Design Capacity is the lesser of (1) the Characteristic Capacity multiplied by the Australian Capacity Factor, and applicable the k modification factors following AS 1720.1 and (2) the Serviceability Capacity which is the load at 6.4mm joint slip, which includes fastener slip, anchor elongation and holdown deformation. Design Capacity is the minimum of test data and structural joint calculation.
The Capacity Factor (φ) is 0.85 for nails and screws for structural joints in a Category 1 application. Reduce tabulated values where other Category applications govern.
Duration of Load Factor (k1) is as shown. Reduce Duration of Load Factor where applicable. Capacities may not be increased.
Timber species for joint design is seasoned Radiata Pine, which is Australia Joint Group JD4 per AS 1720.1 Table H2.4.
The Designer must specify anchor bolt type, length and embedment.
Anchor bolt nut should be finger tight plus 1/3 to 1/2 turn with a hand wrench. Care should be taken not to over-tighten the nut.
Post or beam design by Designer. Posts may consist of multiple members provided they are connected independently of the holdown fasteners.
Structural composite timber columns have sides that either show the wide face or the edges of the timber strands/ veneers, known as the narrow face.
Simpson Strong-Tie stainless-steel connectors require stainless-steel fasteners.
Values in the table reflect installation into the wide face.
Holdowns and tension ties are for use in vertical or horizontal applications.
Holdowns and tension ties may be installed raised up to 460mm above the top of the concrete with no load reduction, provided that additional elongation of the anchor rod is taked into account.

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DTT2 Tension Tie & Holdown