Anchored Masonry Veneers
Words: Dan Kamys
Connectors, Anchors and Fasteners
A brick veneer cavity wall will provide a durable, long-lasting, aesthetically appealing finish to all commercial buildings.
By: Stephen Getz, BSCE
Construction of the veneer on a brick veneer cavity wall relies on quality products and tradesmen to fulfill the design life and functional expectations of the owner and its occupants.
As part of the building's veneer design criteria, the brick tie anchoring system should be carefully evaluated and reviewed with consideration to the following:
- Tie stiffness
- Tie strength
- Tie spacing
- Fastener requirements
- Air barrier interface
- Material type and finish
- Tie versatility.
Construction of brick cavity walls tied to back-up materials other then masonry relies on a relatively stiff brick tie anchoring system for an optimum performing faade. The result minimizes excessive veneer deflection under wind load, which creates less potential for cracking of the veneer. Less cracking means less water migration into the cavity.
A tie illustrating good strength performance characteristics accommodates placement spacing greater than a typical 16- X 16-inch pattern as used with conventional plate and pintle ties, and increases the spacing area to 16 X 24 inches. This generous spacing would remain compliant with standard veneer wall construction requirements of the ACI 530/ASCE 5/TMS 402 criteria. It's important to note that when applying the greater spacing, the quantity of ties required is reduced by almost one-third, which generates a significant cost savings to the owner without compromise to the veneer's performance.
One must also consider a compatible fastener for the connection of the tie assembly to the stud-framing backup. A suitably designed brick anchoring system that utilizes a single fastener for its backup connection will provide a cost-effective installation and lessen the quantity of breaches in the air barrier by 50 percent over conventional ties. A quality Tek screw for steel stud or lag screw for timber connections is efficiently installed and available in material compatible to the anchor plate material.
Finally, the use of insulation in brick veneer cavity wall construction is a popular means to conserve building energy. A tie system must be adaptable for various wall configurations and accommodate insulation of varying thicknesses.
CTP Inc., for example, provides wall ties and anchors that illustrate tie stiffness three times that of conventional ties in the marketplace. The base plate can utilize a single screw fastener for 16-gauge metal stud and timber connections and is manufactured in sizes to bridge various insulation thicknesses. Spacing of the ties is recognized at the maximum permissible by code. The complete assembly is available in hot-dip galvanized or stainless steel finishes. The tie system also utilizes a proprietary multi-functional V-shaped tie that can be used for standard brick veneer construction, or be utilized with reinforcement for seismic applications. The installation is efficient and notably strong.
Stephen Getz, BSCE, is president of Construction Tie Products Inc. For more information, visit www.ctpanchors.com.