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Cold-Formed Steel Connectors – Post Tension Supplemental Information

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<h1>Post-Tension Information</h1>
<div class="row">
    <div class="col-md-8">
      <p><strong>This product is preferable to similar connectors because of a) easier installation, b) higher loads, c) lower installed cost, or a combination of these features.</strong></p>

      <p>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&reg; 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.</p>
      <h5>Features</h5>
      <ul>
        <li>The fastener pattern allows for fastening to the edges of back-to-back studs</li>
        <li>Strap nail slots are countersunk to provide a lower nail head profile</li>
        <li>The slots below the embedment line enable increased front-to-back concrete bond and help to reduce spalling</li>
        <li>Rim joist models accommodate up to a 17" clear span without any loss of strap fastening</li>
      </ul>

      <p>
        <strong>Material:</strong> LSTHD8, LSTHD8RJ &mdash; 14 gauge, all others &mdash; 12 gauge
        <br>
        <strong>Finish:</strong> Galvanized
      </p>

      <h5>Installation</h5>
      <ul>
        <li>Use all specified fasteners; see <a href="/products/connectors/cold-formed-steel-connectors/technical-notes/general-notes">General Notes</a>.</li>
        <li>Use table below for both standard concrete and post-tension slab installations.</li>
        <li>Install before concrete pour with a StrapMate or other holding device.</li>
        <li>Fasten strap from the bottom up.</li>
        <li>Strap may be bent one full cycle (bent horizontal 90&deg; 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.</li>
        <li>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.</li>
        <li>Additional studs attached to the shearwall studs or post may be required by the designer for wall sheathing fastening.</li>
        <li>For installation in severe corrosion environments, refer to <a href="/cipcorrosion">strongtie.com/cipcorrosion</a> for additional considerations.</li>
      </ul>
    </div>
    <div class="col-md-4">
      <div class="row">
        <div class="image col-md-12 col-sm-6 col-xs-6">
          <img alt="STHD" src="https://embed.widencdn.net/img/ssttoolbox/sbqzetvqvq/x200px@2x/STHD8_callout.jpg">
          <div class="image__caption">STHD</div>
        </div>
        <div class="image col-md-12 col-sm-6 col-xs-6">
          <img alt="Typical STHD14RJ Rim Joist Application" src="https://embed.widencdn.net/img/ssttoolbox/yk2zcg26qa/x180px@2x/CF_STHD_InstIll_Ill_Inst_Rimjoist_CY.jpg">
          <div class="image__caption">Typical STHD14RJ Rim Joist Application</div>
        </div>
      </div>
    </div>
  </div>

  <h4>Allowable Stress Design (ASD) Loads for STHD Strap Style Hold-Downs on CFS &mdash; 2,500 psi Concrete</h4>
  <img alt="Allowable Stress Design (ASD) Loads for STHD Strap Style Hold-Downs on CFS &mdash; 2,500 psi Concrete" src="https://embed.widencdn.net/img/ssttoolbox/obbbz05hpo/600px@2x/174a-2020.png">
  <ol>
    <li>Deflection at highest allowable loads for install over CFS double studs are as follows: LSTHD8 = 0.065", STHD10 = 0.096" and STHD14 = 0.115".</li>
    <li>Multiply Seismic and Wind ASD load values by 1.4 or 1.67, respectively, to obtain LRFD capacities.</li>
    <li>Per 2012, 2015 and 2018 IBC Section 1613, detached one- and two- family dwellings assigned to Seismic Design Category (SDC) A, B or C are exempt from the seismic design provisions of IBC Section 1613. For this case, the allowable wind loads apply.</li>
    <li>Minimum center-to-center spacing is 3 times the required embedment (S<sub>min</sub> = 3 x l<sub>e</sub>) for STHD's acting in tension simultaneously. Midwall install is based on 1.5 x l<sub>e</sub> end distance.</li>
    <li>See <a href="/products/fastening-systems">Fastening Systems</a> for more information on Simpson Strong-Tie fasteners.</li>
  </ol>

  <div class="row">
    <div class="col-md-4 col-sm-4">
      <div class="image">
        <img alt="Typical STHD14 Corner Installation on Three Studs" src="https://embed.widencdn.net/img/ssttoolbox/lcfncnezi6/x200px@2x/CF_STHD_InstIll_Ill_Inst_Corner_CY.jpg">
        <div class="image__caption">Typical STHD14 Corner Installation on Three Studs<br>
          (end of wall similar)</div>
      </div>
    </div>
    <div class="col-md-4 col-sm-4">
      <div class="image">
        <img alt="Typical STHD14 Mid-Wall Installation" src="https://embed.widencdn.net/img/ssttoolbox/z18mgd34xj/x200px@2x/STHD_CFS_Midwall_in_callout.jpg">
        <div class="image__caption">Typical STHD14 Mid-Wall Installation</div>
      </div>
    </div>
    <div class="col-md-4 col-sm-4">
      <div class="image">
        <img alt="Typical STHD End Installation" src="https://embed.widencdn.net/img/ssttoolbox/il6oj2hin3/x200px@2x/CF_STHD_InstIll_Ill_Inst_End_CY.jpg">
        <div class="image__caption">Typical STHD End Installation</div>
      </div>
    </div>
  </div>

  <div class="row">
    <div class="col-md-4 col-sm-4">
      <div class="image">
        <img alt="Spalling Load Reduction" src="https://embed.widencdn.net/img/ssttoolbox/oltm33xgbr/x200px@2x/CF_STHD_InstIll_Ill_Inst_Spalling_CY.jpg">
        <div class="image__caption">
          Spalling Load Reduction<br>
          If strap is bent horizontal 90&deg; during installation, and then bent vertical for fastening to the stud, concrete spalling could result. Load reductions may apply, see installation note.
        </div>
      </div>
    </div>
    <div class="col-md-4 col-sm-4">
      <div class="image">
        <img alt="Single-Pour Rebar Installation" src="https://embed.widencdn.net/img/ssttoolbox/hlrmqs0b9z/x200px@2x/CF_STHD_InstIll_Ill_Inst_Singlepour_CY.jpg">
        <div class="image__caption">
          Single-Pour Rebar Installation<br>
          <em>Maintain minimum rebar cover, per ACI-318 concrete code requirements</em>
        </div>
      </div>
    </div>
    <div class="col-md-4 col-sm-4">
      <div class="image">
        <img alt="Two-Pour Installation for Downturn Footings" src="https://embed.widencdn.net/img/ssttoolbox/gyhbpud543/x200px@2x/CF_STHD_InstIll_Ill_Inst_Doublepour_CY.jpg">
        <div class="image__caption">Two-Pour Installation for Downturn Footings</div>
      </div>
    </div>
  </div>
  
  <h4>Spall Reduction System for STHD Holdown</h4>
  <h5>Features</h5>
  <ul>
    <li>Built-in tab</li>
    <li>StrapMate locator line</li>
    <li>Additional diamond hole in RJ versions</li>
  </ul>

  <h5>Benefits</h5>
  <p>Built-in Tab:</p>
  <ul>
    <li>Reduces spalling and costly retrofits.</li>
    <li>No additional labor to install.</li>
    <li>Holds STHD away from form board.</li>
  </ul>

  <p>StrapMate Locator Line:</p>
  <ul>
    <li>Easy inspection to ensure proper location.</li>
    <li>Allows adjustment without removing STHD.</li>
  </ul>

  <p>Additional Diamond Hole:</p>
  <ul>
    <li>One more fastener to help prevent the STHD RJ models from bowing out at the rim joist section.</li>
  </ul>

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