Used to tie the inner wythe (or wall) to the outer wythe for added structural integrity. Masonry ties serve 3 main purposes: provide a sound connection, transfer lateral loads, and to permit in plain movement and/or accomodate differential movement. In order to fulfill the functions a wall tie system must: be securely attached to both wythes, have sufficient stiffness to transfer lateral loads without deformation, have minimum amount of mechanical play, and be corrosion resistant. Ties also allow the mason to build one wyth of a wall to a given height before starting the next, which can lead to increased productivity. Additional ties will commonly be required at control joints, wall intersections, and vertical supports. There are different ties manufactured for different uses:
Corrugated Tie – Are commonly 22 gauge x 7/8″ wide but can come in higher strengths. Corrugated Ties are used most commonly for low-rise residential veneer over wood framed construction with a max air space of 1″. Common spacing is 16″ horizontal and 24″ vertically and the ties are installed with screws or ring shanked nails and within 1/2″ of the 90 degree bend in the anchor.
Z-Tie – Can be a wire-anchor type or flat steel. Z-Ties are fabricated from cold drawn steel at a minimum of 9 gauge and are commonly galvanized for corrosion protection. Typically only used to construct walls with solid units (not less than 75%). Used in walls designed for composite action and not bonded by headers. Z-Ties are also commonly used in intersecting walls with bent ends turning up and/or down into CMU cells which will be grouted solid.
Box (Rectangular) Ties – Composed of wire and are fabricated from cold drawn steel and are commonly galvanized for corrosion protection. can be used with hollow or solid units. Used in walls designed for composite action and not bonded by headers.
Adjustable Tie – Are arguably the most popular as they can be adjusted to suit when the inner and outer with don’t line up exactly right. The more commonly used adjustable ties come in plate type and barrel screw types and can be used with almost any backup type. These ties allow the inner wyth to be constructed faster so the structure can be enclosed quicker. Also since they are 2 piece systems they minimize the risk of damage before the second wythe is constructed. Adjustable ties for steel, concrete, and stud backup commonly have a channel or slot attaching to the inner wall. Adjustable ties for masonry backup are commonly Pintle and Eye arrangements coming in either rectangular or triangle ties with plate or barrel screw type wall anchoring. Max horizontal spacing is commonly 1.77 square feet and max vertical spacing is 16 inches. The bed joint misalignment must not be more than 1.25 inch
Dovetail Anchor – Are most commonly used in applications where the inner wall is concrete with the outer wall being brick or block. There is commonly a reglet cast into the concrete wall which receive the dovetail track which will ultimately receive the tie itself. Different types of dovetail ties are Triangular, corrugated (12 and 16 gauge), and flat anchors (for welding).