ADTT-TZ
Adjustable Deck Tension Tie

Deck collapses are often caused by failure of the connection where the deck is attached to the main structure due to little or no lateral capacity. ADTT-TZ is an Adjustable Deck Tension Tie designed to effectively transfer the out of plane lateral loads of the deck to the house structure.


ADTT-TZ Features:
• Exceeds "Hold-Down Device" requirements per 2015 IRC, Section 507.2.4 [Figure R507.2.3(2)].

• Adjustable design allows lag screw installation at variable distance below deck joist.

• 2-hole break-out washer (BO-W) will work with multiple screw sizes.

• Blocking extensions not required.

Materials: 14 gauge
Finish: G-185 galvanizing

Codes: ESR-3847, FL17324,
L.A. City RR 26048 (ADTT-TZ)

Patents: #9,809,974

Installation:

  • Install with MiTek USP WS8-EXT wood screw or 3/8" HDG lag screw. MiTek USP WS8-EXT or 3/8" HDG lag screws may be installed adjacent or up to 4-3/8" below deck joist (see Figure A).
  • Drive screw horizontally and aligned vertically with the deck joist into the wall top plate of the main (house) structure.
  • Install four (4) of the specified joist fasteners into vertical legs (Two (2) on each side of deck joist).
  • Secure front brace with six (6) specified joist fasteners.
  • Re-tighten the MiTek USP WS8-EXT or 3/8" HDG lag screw as needed to fully engage with the ADTT-TZ. DO NOT OVERDRIVE. Note: Minimum 3" thread penetration required for proper installation of the MiTek USP WS8-EXT or HDG lag screw.
  • For detailed installation instructions refer to MiTek-US.com.
1) Allowable loads are for the ADTT-TZ installed tight to the bottom of the joist (Contracted) or 4" from bottom of joist to ADTT-TZ bend line (Extended).
2) Deflections are derived from static, monotonic load tests of devices connected to DF wood members with specified fasteners.
3) WS8-EXT is a 1/4" dia. x 8" long double barrier coated screw sold by MiTek and must be ordered separately if not purchasing the kit. The minimum thread penetration into the top plate of the wall framing is 3".
4) 3/8" HDG Lag Screw is an ASTM A307 Grade A lag screw with a thread diameter of 3/8" and is hot-dip galvanized to ASTM A153 standards. The minimum thread penetration into the top plate of the wall framing is 3". Lag screws are available at your local hardware store and must be purchased separately. 
5) Check with your siding manufacturer for recommendations for fastening through your siding material. 
6) LL915 denotes a MiTek USP LumberLok Screw, #9 x 1-3/8" long and must be ordered separately if not purchasing the kit. 
7) ADTT-TZKT is a kit with (4) ADTT-TZ packaged with MiTek USP WS8-EXT screws and MiTek USP LL915 LumberLok screws. 
8) Nails: 10d x 1-1/2 nails are 0.148" dia. x 1-1/2" long. 
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