Simpson Strong-Tie Wood Construction Connectors

Simpson Strong-Tie ® Wood Construction Connectors

General Information and Notes

Holdowns and tension ties represent key components that comprise a continuous load path. In light-frame construction, holdowns are typically used to resist uplift due to shearwall overturning or wind uplift forces. In panelized roof construction, holdowns are used to anchor the concrete or masonry walls to the roof framing. Holdowns can be separated into two categories — post-installed or cast-in-place. Cast-in-place holdowns, such as the STHD holdowns or the PA purlin anchors are installed at the time of concrete placement and attached to wood framing with nails. Cast-in-place holdowns are an economical anchorage solution with allowable loads up to 5,300 lb.

After the concrete has been placed, post-installed holdowns are attached to anchor bolts during wall framing. They are attached to the wood framing with nails, Strong-Drive ® SD Connector screws and Strong-Drive SDS Heavy-Duty Connector screws or bolts. Post-installed holdowns have have allowable loads ranging from about 850 lb. up to nearly 20,000 lb. The Post-to-Foundation Designer is a quick way to specify a holdown and the applicable anchorage to meet your project design requirements. Visit app.strongtie.com/pfd .

Holdowns and Tension Ties

Shear from diaphragm

Tension in collector

Compression in collector

Force applied by sheathing nails

Height (h)

Embedded holdown

Holdown with threaded anchor

Threaded rod with bearing plate

Length (b)

Methods of Providing Overturning Restraint

Shear restraint from anchor rods

Compression post restraint (C)

Overturning uplift restraint (T)

Idealized Force Diagram on Full-Height Shearwall Segment (sheathing not shown)

Post-to-Foundation Designer app.strongtie.com/pfd

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Site-Built Shearwall Designer strongtie.com/webapps/sitebuiltshearwalldesigner

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