In this guide, a masonry system is defined as an above-grade exterior wall assembly that includes masonry as the primary cladding element. Masonry wall systems are designed for the local climate or microclimate where the system will be installed. A masonry system considers how all wall components (e.g., water control and air control layers, cladding attachment and supports, veneer products, etc.) are integrated and made continuous with all other wall elements, including the field-of-wall area and its relationship to wall penetration and transition details.
The wall systems featured in this guide include anchored masonry veneer with concrete, CMU, steel stud-framed, or wood-framed backup wall structures as depicted in Fig. 2-2. These systems are discussed in Chapter 6 and allow for alternative veneer and insulation options from those shown.
Also featured in this guide is a single-wythe CMU wall system with insulation interior of CMU. This system is depicted in Fig. 2-2 and is discussed in Chapter 7. Various interior insulation options are also described within this chapter.
Selecting a Masonry System
This chapter describes and compares anchored masonry veneer and single-wythe CMU wall systems according to several comparison categories. This comparison is provided in a System Comparison Matrix on Table 2-1, which may be used to assist with the initial selection of an appropriate masonry system(s) for a particular project. The comparison categories are:
Maximum Building Height
The maximum building height recommended for each system is provided. These are determined by typical wind pressures, common building shape/form, and accessibility for material installation and long-term maintenance needs. Building height definitions vary throughout the industry; however, in this guide, building height is classified by low-, mid-, and high-rise and is further described in the legend of the System Comparison Matrix. Some systems may be used for buildings of greater height than that identified within the matrix; however, these applications should be carefully evaluated by the project’s design team.
Typical Assembly Thermal Performance
Defines the typical effective R-value for the field-of-wall area. The R-value range provided accounts for the thermal resistance of the wall layers (including equivalent interior and exterior air films) but also includes the three-dimensional effect of standard repetitive framing (e.g., Steel studs and tracks), and cladding attachments such as masonry anchors. Within the system comparison matrix, the R-value provided assumes no major conductive penetrations such as balconies, shelf angles, or floor line transitions.
For veneer systems, it is assumed that framed wall cavities contain insulation and that exterior insulation is of a thickness that may be reasonably installed using typical construction practices of Colorado and southern Wyoming.
For single-wythe wall applications, typical R-values assume an 8-inch CMU wall and interior insulation types and thicknesses that may be reasonably installed using typical construction practices of Colorado and southern Wyoming.
Thermal performance of any system can vary with wall depth, insulation type and thickness, or cladding attachment methods. Refer to Chapter 8 for more discussion on the thermal performance of these systems and for effective R-value design tables.
Cladding Attachment (Lateral Loads)
Defines the attachment method used to laterally support the masonry veneer (where applicable).
Cladding Support (Gravity Loads)
Defines the method used to support the gravity loads of the masonry component of the system.
Fire-Resistance Rating
Defines the ability of a building element or assembly to withstand exposure to a fire without passage of excessive heat, hot gases, or flames while continuing to provide sufficient structural stability. Typical ratings are shown. Single-wythe backup wall systems assume an 8-inch-wide CMU wall; thicker CMU walls may achieve a higher rating.
Chapter Reference
1. The Masonry Society. TMS-402-16 Building Code
Requirements for Masonry Structures. (n.p.: The Masonry
Society, 2016).
OUR SPONSORS
