LSTHD/STHD Strap Tie Holdown

Installation

View step-by-step installation instructions

The STHD is an embedded strap-tie holdown offering high load capacity and a staggered nail pattern to help minimize splitting. 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.

STHD8 and STHD8RJ Discontinued in 2011

The STHD8 and STHD8RJ models are being phased out in favor of the LSTHD8 and LSTHD8RJ. They no longer appear in load table below, but are listed in ICC-ES ESR-2920.

Features

The nailing pattern allows for nailing to the edges of double 2x's
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 nailing

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.
Nail 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. Any portion of the strap left exposed should be protected against corrosion.
Unless otherwise noted, 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 nailing.
Wood shrinkage after strap installation across horizontal members may cause strap to buckle outward.

roll over images below to see larger image


STHD U.S. Patent 5,813,182	Nails are countersunk for a low profile strap surface.	Typical STHD14RJ Rim Joist Application


Typical STHD14 Corner Installation	Typical STHD14 Mid Wall Installation	Typical STHD14 End Wall Installation


Single Pour Rebar Installation *Maintain minimum rebar cover, per ACI-318 concrete code requirements.	Typical STHD Application Over Sheathing	STHD Over Shearwall Diaphragm

top Spall Reduction System for STHD Strap Tie Holdown:


SM1 U.S. Patent 6,796,099

Features and Benefits Built-in Tab: Reduces spalling and costly retrofits. No additional labor to install. Holds STHD away from form board. StrapMate® Locator Line: Easy inspection to ensure proper location. Allows adjustment without removing STHD. Additional Diamond Hole in RJ versions: One more fastener to help prevent the STHD RJ models from bowing out at the rim joist section.

Allowable loads are for wind or seismic loading. Nail quantities reflect an increase for duration of load with no further increase allowed. Reduce where other loads govern.
Concrete shall have a minimum concrete strength, f'c of 2500 psi.
10d common (3" long x 0.148" diameter) nails may be used with no load reduction. 10dx2 1/2 (2 1/2" long x 0.148" diameter) nails may be used with no load reduction when installed directly over framing. For installation over structural sheathing, use 10d common or 16d sinkers.
Use the specified number of nails listed in table or as specified. In many cases, not all nail holes will be filled. Nail strap from the bottom up.
The Designer may specify a reduced quantity of nails for some applications.
Deflection at highest allowable loads for install over wood double studs are as follows: Installed on framing: LSTHD8 = 0.089", STHD8 = 0.085", STHD10 = 0.117" and STHD14 = 0.118" Installed over structural sheathing: LSTHD8 = 0.114", STHD8 = 0.123", STHD10 = 0.146" and STHD14 = 0.164".
Multiply Seismic and Wind ASD load values by 1.4 or 1.6 respectively to obtain LRFD capacities.
Per 2006 and 2009 IBC Section 1613.1, detached one- and two-family dwellings in Seismic Design Category (SDC) C may use "Wind and SDC A&B" allowable loads.
Minimum center-to-center spacing is 3 times the required embedment (S_min = 3 x l_e) for STHD's acting in tension simultaneously. Midwall install is based on 1.5 x l_e end distance.
See T-SCLCOLUMN for installation on structural composite lumber posts or columns.
NAILS: 16d sinker = 0.148" dia. x 3 1/4" long. See other nail sizes and information.

					Legacy Reports
	IAPMO ES ER	ICC-ES ESR	CITY OF LOS ANGELES	STATE OF FLORIDA	ICC-ES NER	ICC-ES ER	ICC-ES ES
LSTHD	See specific model numbers for code listings.
LSTHD8		ESR-2920 / ESR-2523 *
LSTHD8RJ		ESR-2920 / ESR-2523 *
STHD	See specific model numbers for code listings.
STHD10		ESR-2920 / ESR-2523 *
STHD10RJ		ESR-2920 / ESR-2523 *
STHD14		ESR-2920 / ESR-2523 *
STHD14RJ		ESR-2920 / ESR-2523 *
STHD8		ESR-2920 / ESR-2523 *
STHD8RJ		ESR-2920 / ESR-2523 *

* 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

Download the Simpson Strong-Tie™ AutoCad® Menu, which allows you to insert Ortho views directly into your AutoCAD drawing.

	ORTHOGRAPHIC	PERSPECTIVE
LSTHD	None for this model	Post Tension Garage Footing: DWG \| DXF Post Tension Corner Install: DWG \| DXF Post Tension Top View: DWG \| DXF
LSTHD8	LSTHD8: DWG \| DXF LSTHD8 front view: DWG \| DXF LSTHD8 left view: DWG \| DXF LSTHD8 right view: DWG \| DXF	None for this model
LSTHD8RJ	None for this model	None for this model
STHD	None for this model	High Wind-Resistant Construction D86: Holdowns: Typical STHD 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: DWG \| DXF STHD10 front view: DWG \| DXF STHD10 right view: DWG \| DXF	None for this model
STHD10RJ	STHD10RJ: DWG \| DXF STHD10RJ front view: DWG \| DXF STHD10RJ right view: DWG \| DXF	None for this model
STHD14	STHD14: DWG \| DXF STHD14 front view: DWG \| DXF STHD14 right view: DWG \| DXF	None for this model
STHD14RJ	STHD14RJ: DWG \| DXF STHD14RJ front view: DWG \| DXF STHD14RJ right view: DWG \| DXF	High Wind-Resistant Construction D85: Holdowns: DWG \| DXF STHD14RJ: DWG \| DXF
STHD8	STHD8: DWG \| DXF STHD8 front view: DWG \| DXF STHD8 right view: DWG \| DXF	High Wind-Resistant Construction D52: Header to Wall Framing: DWG \| DXF
STHD8RJ	STHD8RJ: DWG \| DXF STHD8RJ front view: DWG \| DXF STHD8RJ right view: DWG \| DXF	None for this model