LTT/MTT/HTT Tension Ties

LTT20B
(LTT19 similar)

HTT22
(HTT16 similar)
U.S. Patent 5,467,570

Horizontal LTTI31 Installation

Horizontal LTT19 Installation
(LTT20B similar)

Vertcal HTT22 Installation

Tension ties offer a solution for resisting tension loads that can be nailed to the stud.

The HTT22 is a single-piece formed tension tie - no rivets, and a 4-ply formed seat which won't unfold during loading. No washers required. The LTT19 Light Tension Tie is designed for 2x joists or purlins and the LTT20B is for nail- or bolt-on applications. The 3" nail spacing makes the LTT20B suitable for wood I-joists if 10dx1 1/2" nails are substituted for the specified 16d's with a reduced load.

The LTTI31 is designed for wood chord open web truss attachments to concrete or masonry walls and may also be installed vertically on a minimum 2x6 stud.

Material: See table.

Finish: Galvanized. May be ordered HDG; contact Simpson.

Installation:

Use all specified fasteners. See General Notes.
Use the specified number and type of nails to attach the strap portion to the top or side of purlin or beam with the exception of LTT19, a minimum 4x width is required for attachment. Minimum 2x width required for LTT19.
Do not install LTT and MTT tension ties raised.
The HTT22 can be substituted for the MTT28B.
See Adhesive Solutions for tested, load-rated adhesive anchors for anchor bolt options.
To tie double 2x members together, the Designer must determine the fasteners required to bind members to act as one unit without splitting the wood.
Refer to technical bulletin T-ANCHORSPEC for post-installed anchorage solutions.

roll over images below to see larger image

For tension ties, per ASTM test standards, anchor bolt nut should be finger-tight plus 1/3 to 1/2 turn with a hand wrench, with consideration given to possible future wood shrinkage. Care should be taken to not over-torque the nut. Impact wrenches should not be used.

DO NOT MODIFY THE MTT28B.

Do not rotate the MTT28B's strap around the rivet.

The strap must be in line vertically with the body of the holdown to achieve table loads.

Allowable loads for HTT are based on the lower of the NDS fastener values or the ultimate load on a steel test jig divided
by 2.5.
Alternate fasteners may be installed, provided the appropriate reductions are applied (use face mount hanger reduction).
The Designer must specify anchor bolt type, length and embedment (see T-ANCHORSPEC).
Allowable loads have been increased for earthquake or wind load durations with no further increase allowed; reduce where other load durations govern.
Bolt values are based on a minimum lumber thickness of 1 1/2".
If a 1/2" or 5/8" anchor bolt is used for the LTT19 or LTT20B, add a standard cut washer to the seat. No additional washer is required for a 3/4" anchor bolt. See table for appropriate anchor bolt sizes.
HTT’s may be raised off sill plate. Refer to note q, Instructions for the Installer for installation instructions of raised holdowns
Post design shall be by Designer.
Deflection at Highest Allowable Tension Load includes fastener slip, holdown elongation, and anchor bolt elongation (L = 5").
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.
NAILS: 16d = 0.162" dia. x 3 1/2" long, 10dx1 1/2 = 0.148" dia. x 1 1/2" long, 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
HTT	See specific model numbers for code listings.
HTT16			RR25318	FL503		ER-5313
HTT22			RR25293 / RR25318	FL503		ER-5708
LTT	See specific model numbers for code listings.
LTT19			RR24818	FL474	NER-393	ER-5708
LTT20B			RR24818	FL474	NER-393	ER-5708
LTTI31			RR24818	FL474	NER-432	ER-5708
MTT	See specific model numbers for code listings.
MTT28B				FL503		ER-5708