LSTHD/STHD Strap Tie Holdown

Installation

View step-by-step installation instructions

The STHD is an embedded strap tie holdown with high load capacity and a staggered nail pattern to help minimize splitting. The STHD strap tie holdown incorporates many features that improve installation and function. When used in conjunction with the StrapMate® you have a system that prevents both parallel and perpendicular movement during installation relative to the form. Allows for accurate location of the STHDs and reduces the possibility of spalling.

Features

The strap nailing pattern allows for nailing to the edges of double 2x's.
A slot below the embedment line allows for increased front to back concrete bond and reduced spalling.
Strap nail slots are countersunk to provide a lower nail head profile.
Rim joist models accommodate up to a 17" clear span without any loss of strap nailing.

Material: LSTHD8, LSTHD8RJ - 14 ga, all others - 12 ga.

Finish: Galvanized

Installation:

Use all specified fasteners. See General Notes.
See Post Tension information.
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 palling behind the strap. If the spall is 1" or less, measured from the embedment line to the bottom of the spall, full loads apply. For larger spalls see table footnotes for load reduction. Any portion of the strap left exposed should be protected against corrosion.
For two pour installations spalling is measured from the first pour.
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.
To tie multiple 2x members together, the Designer must determine the fasteners required to join members to act as one unit without splitting the wood.
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 STHD Applications (for two pour, see footnote 5.)


Typical STHD14RJ Rim Joist Application	Typical STHD14 End Installation (No corner return)	Single Pour Rebar Installation	Two Pour Rebar Installation
		*Maintain minimum rebar cover, per ACI-318 concrete code requirements.

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.

'RJ' after the model indicates STHDs for rim joist applications, e.g. STHD8RJ.
STHD14RJ on 8" stemwall requires 30-16d sinkers.
10d commons nails may be used with no load reduction.
Minimum nail end distance to prevent splitting is 10 x diameter, 1 1/2" for 16d sinkers and 10d common.
For two pour with 4" slab or less. The STHD14 load at 1/2" end distance 2000 psi is 3235 lbs. and 4220 lbs. at 14" end distance. The STHD10 at the same condition is 2035 lbs. for 1/2" end distance, and 2750 lbs. at 10" end distance.
Allowable loads have been increased for wind or earthquake load durations with no further increase allowed; reduce where other load durations govern.
Where fewer fasteners are used in the structural wood member, reduce loads according to the code.
To get the full table load, the minimum center-to-center spacing is twice the embedment depth when resisting tension loads at the same time.
There is an increase in the amount of deflection if the strap is installed on the outside of the shear panel instead of directly to the framing. Refer to technical bulletin T-PLYWOOD.
Calculate loads using straight line interpolation for corner distances between 1/2" and l_e.
STHD14RJ installed on HF/SPF in an 8" stemwall: the l_e load is 5370 lbs.
Post design shall be by Designer.
Loads shown apply to post tension slabs when one #4 rebar (minimum) is installed as in detail 1.
Structural composite lumber columns have sides that show either the wide face or the edges of the lumber strands/veneers. Values in the tables reflect installation into the wide face. See technical bulletin T-SCLCOLUMN for values on the narrow face (edge).
For concrete spalls between 1" and 4" the allowable loads is 0.90 of the table loads.
Table loads apply to corner stemwall applications provided that there is a perpendicular stemwall at the corner having a minimum length of l_e. See tables for loads where there is not a perpendicular stemwall at corners.
Testing to new ICC-ES acceptance criteria to be completed in 2009. Reference this web site for the latest loads and information.
NAILS: 16d sinker = 0.148" dia. x 3 1/4" long. See other nail sizes and information.

Download the Simpson 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

					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						ER-5349
LSTHD8RJ						ER-5349
STHD	See specific model numbers for code listings.
STHD10						ER-5349 / ER-5275
STHD10RJ						ER-5349
STHD14						ER-5349 / ER-5275
STHD14RJ						ER-5349
STHD8						ER-5349 / ER-5275
STHD8RJ						ER-5349