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LSTHD/STHD Strap-Tie Holdowns

LSTHD/STHD

Holdowns and Tension Ties

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The STHD is an embedded strap-tie holdown offering high-load capacity. The STHD incorporates many features that aid correct installation and improve performance. When installed on the forms with the StrapMate® strap holder, the unique design of the STHD delivers enhanced stability before and during the pour to help prevent both parallel and perpendicular movement (relative to the form). This results in accurate positioning of the strap and reduced possibility of spalling.

Key Features

  • The fastener pattern allows for fastening to the edges of back-to-back studs
  • Strap nail slots are countersunk to provide a lower nail head profile
  • The slots below the embedment line enable increased front-to-back concrete bond and help to reduce spalling
  • Rim joist models accommodate up to a 17" clear span without any loss of strap fastening

Material

  • LSTHD8, LSTHD8RJ — 14 gauge; all others — 12 gauge

Finish

  • Galvanized

Installation

  • Use all specified fasteners; see General Notes.
  • Use table below for both standard concrete and post-tension slab installations.
  • Install before concrete pour with a StrapMate or other holding device.
  • Fasten strap from the bottom up.
  • Strap may be bent one full cycle (bent horizontal 90° then bent vertical) to aid wall placement, but may cause spalling behind the strap. If the spall is 1" or less, measured from the embedment line to the bottom of the spall, full loads apply. 1" to 4" spalls for LSTHD8 achieve 0.9 times table loads. STHD10 and STHD14 achieve full load for spalls less than 4". Any portion of the strap left exposed should be protected against corrosion.
  • Other than where noted in the two-pour detail, do not install where: (a) a horizontal cold joint exists within the embedment depth between the slab and foundation wall or footing beneath, unless provisions are made to transfer the load, or the slab is designed to resist the load imposed by the anchor; or (b) slabs are poured over concrete block foundation walls.
  • Additional studs attached to the shearwall studs or post may be required by the Designer for wall sheathing fastening.
  • For installation in severe corrosion environments, see Corrosion Information.

Related Literature

Load Tables

For SI: 1 in = 25.4 mm, 1 lb. = 4.45 N, 1 psi = 6.895 kPa.

  1. Deflection at highest allowable loads for install over CFS double studs are as follows: LSTHD8 = 0.065", STHD8 = 0.071", STHD10 = 0.096" and STHD14 = 0.115".
  2. Multiply Seismic and Wind ASD load values by 1.4 or 1.6 respectively to obtain LRFD capacities.
  3. Per 2009 and 2013 IBC Section 1613, detached one- and two-family dwellings in Seismic Design Category (SDC) C may use "Wind and SDC A&B" allowable loads.
  4. Minimum center-to-center spacing is three times the required embedment (Smin = 3xle) for STHDs acting in tension simultaneously. Mid-wall install is based on 1.5xle end distance.
  5. See more information on Simpson Strong-Tie fasteners.

Code Reports

Part IAPMO UES ER ICC-ES ESR City of Los Angeles State of Florida
LSTHD8 ESR-2920 ESR-2523 FL13326
LSTHD8RJ ESR-2920 ESR-2523 FL13326
STHDSee specific model numbers for code listings.
STHD10 ESR-2920 ESR-2523 FL13326
STHD10RJ ESR-2920 ESR-2523 FL13326
STHD14 ESR-2920 ESR-2523 FL13326
STHD14RJ ESR-2920 ESR-2523 FL13326

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
S/HPAHD22None None
STHDNone
High Wind-Resistant Construction D109: Holdowns: Typical STHD Corner Installation
DWG DXF
Floor to Floor Connections
DWG DXF
Post Tension Garage Footing
DWG DXF
Post Tension Corner Install
DWG DXF
Post Tension Top View
DWG DXF
STHD With Concrete Spalling
DWG DXF
STHD Edge Installation
DWG DXF
STHD10
STHD10
DWGDXF
STHD10 front view
DWG DXF
STHD10 right view
DWG DXF
None
STHD10RJ
STHD10RJ
DWGDXF
STHD10RJ front view
DWG DXF
STHD10RJ right view
DWG DXF
None
STHD14
STHD14
DWGDXF
STHD14 front view
DWG DXF
STHD14 right view
DWG DXF
None
STHD14RJ
STHD14RJ
DWGDXF
STHD14RJ front view
DWG DXF
STHD14RJ right view
DWG DXF
High Wind-Resistant Construction D104: Holdowns
DWG DXF
STHD14RJ
DWG DXF
STHD8
STHD8
DWGDXF
STHD8 front view
DWG DXF
STHD8 right view
DWG DXF
None
STHD8RJ
STHD8RJ
DWGDXF
STHD8RJ front view
DWG DXF
STHD8RJ right view
DWG DXF
None