Some unique features of the Simpson Strong-Tie STHD Strap Tie Holdown:

• 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.

Contractors should also take note of some important installation information, provided on the Simpson Strong-Tie Website.  Important tips include:  Where fewer fasteners are used in the structural wood member, reduce loads according to the code.  Also, 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. 

In addition, wood shrinkage after strap installation across horizontal members may cause strap to buckle outward. 

Finally, it is highly recommended that the Simpson Strong-Tie STHD Strap Tie Holdown be used in conjunction with approved associated devices such as the StrapMate ® for maximum efficiency and safety.