The HHDQ series of holdowns combines low deflection and high loads with ease of installation. The unique seat design of the HDQ8 greatly minimizes deflection under load. Both styles of holdown employ the Simpson Strong-Tie® Strong-Drive® SDS Heavy-Duty Connector screws which install easily, reduce fastener slip and provide a greater net section when compared to bolts. They may be installed either flush or raised off the mudsill without a reduction in load value.
- Uses Strong-Drive SDS Heavy-Duty Connector screws which install easily, reduce fastener slip and provide a greater net section area of the post compared to bolts
- Strong-Drive SDS Heavy-Duty Connector screws are supplied with the holdowns to ensure proper fasteners are used
- No stud bolts to countersink at openings
- HDQ8 — 7 gauge; HHDQ — body: 7 gauge, washer: 1/2" plate
- HDQ8 — galvanized; HHDQ — Simpson Strong-Tie® gray paint; HHDQ11 — available in stainless steel
- Use all specified fasteners; see Holdown and Tension Tie General Notes
- No additional washer is required
- Strong-Drive SDS Heavy-Duty Connector screws install best with a low-speed high-torque drill with a 3/8" hex-head driver
- 5/8" of adjustability perpendicular to the wall
- No additional washer is required
- HHDQ14 requires a heavy-hex anchor nut (supplied with holdown)
Installer's Pocket GuideS-C-INSTALL16S-C-INSTALL16 is a guide featuring updated products, new color illustrations and easier navigation. Some popular structural fastening and anchoring products have also been added.Installation Guide
Anchoring Solutions for Simpson Strong-Tie® Connectors in Wind and Low-Seismic RegionsT-ANCHORSPEC12A cross-reference to help evaluate the anchorage solution options for Simpson Strong-Tie holdowns, tension ties and post bases. Extensive details included for various foundation types.Technical Bulletin
City of Los Angeles RR Values for Connectors in Shear Walls and Wall Anchorage AssembliesT-C-HDLA15T-C-HDLA15 is a technical bulletin that details holdown requirements imposed by the City of Los Angeles and provides adjusted load values for Simpson Strong-Tie holdowns that meet these requirements.Technical Bulletin
Connectors Installed on SCL ColumnsT-C-SCLCLM16A one-page, single-sided technical bulletin discussing the structural properties of the two different surface sides of SCL columns, including the listing of reduction factors.Technical Bulletin
Panelized Roof SystemsT-C-PRS15Learn about the guidelines for designing and installing our connectors to meet the requirements of the 2009 IBC for structures using panelized wood roof systems with concrete or masonry walls.Technical Bulletin
Connectors Installed on SCL ColumnsT-C-SCLCLMCAN17A one-page Canadian Limit States version of the technical bulletin discussing the structural properties of two different surface sides of columns made from structural composite lumber (SCL).Technical Bulletin
Stainless-Steel HoldownsL-C-SSHD16Simpson Strong-Tie® Stainless-Steel HoldownsEngineering Letter
Holdown Anchors: Slab-on-GradeL-C-HDABSOG17Anchor Bolt Recommendations for Holdowns Used with Slab-On-Grade Foundations.Engineering Letter
Holdown Anchors: StemwallL-C-HDABSTEM15Anchor Bolt Recommendations for Holdowns Used with Stemwall FoundationsEngineering Letter
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- See Holdown and Tension Tie General Notes.
- Noted HHDQ14 allowable loads are based on a 5 1/2" wide post (6x6 min.) Other loads based on 3 1/2" wide post minimum.
- HHDQ14 requires heavy-hex anchor nut (supplied with holdown).
- HDQ and HHDQ installed horizontally achieve compression loads with the addition of a standard nut on the underside of the load transfer plate. Refer to ICC-ES ESR-2320 for design values. HDQ8 requires a standard nut and BP7/8-2 (sold separately) load washer on the underside of the holdown for compression load. Design of anchorage rods for compression force shall be per the Designer.
|Part||IAPMO UES ER||ICC-ES ESR||City of Los Angeles||State of Florida|
|HHDQ||See specific model numbers for code listings.|
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