Thin veneers have allowed for new, innovative methods and systems. While the most common installation method used today is to anchor veneers to wood stud, metal stud, or concrete masonry backup systems, let's take a look at four other popular systems and how they're used.
Adhered Veneers
Over the past decade and a half, adhered veneers have become quite popular. Adhered veneer is veneer set in a bed of mortar, that is “secured to and supported by the backing through adhesion.” This is also commonly known as "lick and stick".
The council offers the following model for an adhered exterior veneer in order to provide adequate moisture control, maintaining that the general design requires the veneer’s backing system must resist water penetration and that flashing must be properly detailed complete with weep holes to redirect water to the outside of the structure. Oriented Strand Board (OSB) is installed as sheathing on the outer face of the studs, followed by two layers of building paper, and then a drainage mat is installed to drain any water that has penetrated to the flashing which in turn sends it to the building exterior via the weepholes. Atop the drainage mat, a galvanized expanded metal lath, or diamond mesh, should be attached as it will hold the veneer to the studs. A parging backing, which is a thin coat of mortar that provides a smooth surface for masonry and seals it against moisture, should be applied onto the mesh. Mortar is applied to the back of the thin veneer and pressed on to the parged surface.
The council cautions that drainage is often the key missing element in adhered veneer systems, and that it is the designer’s responsibility to assure that an adequate drainage system with proper flashing and correct spacing of nails is included.
Mounting System
Another option for affixing masonry veneers is a lightweight system that works in conjunction with traditional mortar to secure the veneer, while reducing footing and lintel requirements, and labor and installation costs. This type of system offers a mechanical support and spacing panel in which each unit is supported by ties that mechanically interlock the masonry veneer to the panel which is anchored to the wall.
Multiple support tie face heights are available, and the support tie configuration is placed at an acute angle, allowing the mortar to surround the support tie, which results in a positive masonry lock between the brick mortar and panel. Systems can be customized based on what the project requires. A few examples of how a project can be customized:
- Galvanized steel to prevent rust and distribute heat
- Embossed texture creates a built in weep system
- Use of rainscreen technology to improve drainage and ventilation
Track System
Track systems are used to hang thin veneer from either a vertical or horizontal application in situations without a conventional perimeter concrete footing to support the weight of the veneer used. Brackets are mounted onto walls, either exterior or interior, as support for masonry panels.
Prior to installing the bracket system, it is important to assure that the backing wall surfaces are smooth, flat, clean, and free of all debris. Furring may be necessary where the backing wall is not acceptable for direct attachment of the bracket system, and it is the engineer’s responsibility to determine the backing wall’s structural integrity based on the load imposed by the system panels and other applicable material, live, seismic, snow, and wind-loading conditions. It is important to evaluate not only the structural integrity of the backing wall, but also its capability to resist and drain moisture. Building wrap or other sheathing materials should be properly installed to the wall surface as needed to assure an adequate moisture barrier.
Insulated Wall System
Another option that is rapidly gaining ground is the foam masonry panel system. These total cladding systems are designed to provide better insulation and consist of foam panels, stainless steel screws or anchors, and mortar, with the foam panel systems able to accommodate a variety of masonry units.
Insulated wall systems take advantage of rigid foam, which provides quite a few benefits:
- Because the foam covers the framing elements, the thermal bridging of cavity insulation is often eliminated. This results in an R-Value as high as R-13 outside the framing.
- Resistance to wind speeds exceeding 110 mph .
- Increased sound reduction. A big plus in multifamily structures as loud sounds will only be faintly heard, leaving occupants with a quiet dwelling.
- Higher fire resistance. In rigorous testing, per NFPA 285 and ASTM E119 standards, these systems have withstood hour-long exposure to temperatures exceeding 1,700°F.
Each system has subtle differences that can impact the overall cost and speed of a project. Based on the requirements of the building, it's first important to understand the features of each and system and then picking the right one based on your needs. Be sure you know everything you need to know to choose and correctly implement the right system, download our guide to masonry veneers.
