LSTHD/STHD Strap Tie Holdown

The STHD is an embedded strap tie holdown with high load capacity and a staggered nail pattern to help minimize splitting. The latest version of the STHD strap tie holdowns incorporates many new 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 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. 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, with the (l_e) load at 133% of 4960 lbs.
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 earthquake or wind 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.
STHD14 and STHD14RJ installed on HF/SPF in an 8" stemwall: the l_e load is 5280 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.For concrete spalls between 1" and 4" the allowable loads is 0.90 of the table loads.
For concrete spalls between 1" and 4" the allowable loads is 0.90 of the table loads.
Table loads apply to stemwall applications provided there is a minimum end distance of l_e. See table for loads when installed less than l_e.
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				FL503		ER-5349
LSTHD8RJ				FL503		ER-5349
STHD	See specific model numbers for code listings.
STHD10				FL503 / FL9601		ER-5275 / ER-5349
STHD10RJ				FL503 / FL9601		ER-5349
STHD14				FL503 / FL9601		ER-5275 / ER-5349
STHD14RJ				FL503 / FL9601		ER-5349
STHD8				FL503 / FL9601		ER-5275 / ER-5349
STHD8RJ				FL503 / FL9601		ER-5349