Masonry veneer walls consist of a single non-structural external layer of masonry

Masonry

Masonry is the building of structures from individual units laid in and bound together by mortar; the term masonry can also refer to the units themselves. The common materials of masonry construction are brick, stone, marble, granite, travertine, limestone; concrete block, glass block, stucco, and...

 work, typically brick

Brick

A brick is a block of ceramic material used in masonry construction, usually laid using various kinds of mortar. It has been regarded as one of the longest lasting and strongest building materials used throughout history.-History:...

, backed by an air space. The innermost element is usually structural, and may consist of wood or metal framing or masonry. Walls constructed in this manner have several advantages over solid masonry, some of which are shared with the Cavity wall

Cavity wall

Cavity walls consist of two 'skins' separated by a hollow space . The skins are commonly masonry such as brick or concrete block. Masonry is an absorbent material, and therefore will slowly draw rainwater or even humidity into the wall. The cavity serves as a way to drain this water back out...

 (where inner and outer layers are both structural) while others are distinct to masonry veneer walls:

• The airspace functions as a drainage plane, allowing any water that has penetrated the veneer to drain to the bottom of the cavity, where it encounters flashing (weatherproofing)
  Flashing (weatherproofing)
  Flashing refers to thin continuous pieces of sheet metal or other impervious material installed to prevent the passage of water into a structure from an angle or joint...
  
   and is directed to the outside through weep
  Weep
  A weep or a weep-brick is a small opening that allows water to drain from within an assembly. Weeps are located at the bottom of the object to allow for drainage; the weep hole must be sized adequately to overcome surface tension....
  
   holes, rather than entering the building.

• The cavity can include insulation
  Building insulation
  building insulation refers broadly to any object in a building used as insulation for any purpose. While the majority of insulation in buildings is for thermal purposes, the term also applies to acoustic insulation, fire insulation, and impact insulation...
  
  , which is typically in the form of rigid foam, increasing the thermal performance of the wall.

• The structural framing
  Framing (construction)
  Framing, in construction known as light-frame construction, is a building technique based around structural members, usually called studs, which provide a stable frame to which interior and exterior wall coverings are attached, and covered by a roof comprising horizontal ceiling joists and sloping...
  
   or masonry backup can be erected first to allow the rest of the building structure to be completed concurrently with the outer veneer, rather than waiting for the entire wall structure to be completed before proceeding with the roof and upper floors.

• A masonry veneer wall can be completed in a shorter time with less labor than a solid masonry wall thus saving in cost.

• The weight of a veneer wall can be significantly less than solid masonry, resulting in economies in foundations and structural support.

Support

Because the masonry veneer is non-structural, it must be tied back to the building structure to prevent movement under wind and earthquake

Earthquake

An earthquake is the result of a sudden release of energy in the Earth's crust that creates seismic waves. The seismicity, seismism or seismic activity of an area refers to the frequency, type and size of earthquakes experienced over a period of time...

 loads. This is usually accomplished by a means that does not interrupt the drainage plane and does not compromise cavity insulation. Brick ties are used for this purpose, and may take the form of corrugated metal straps nailed or screwed to the structural framing, or as wire extensions to horizontal joint reinforcement in a fully masonry veneer system. Additionally, the veneer is vertically self-supporting over relatively short heights, so shelf angle

Shelf angle

In masonry veneer building construction, a shelf angle is a steel angle which supports the weight of brick or stone veneer and transfers that weight onto the main structure of the building.-Background:...

s or relieving supports must be provided, typically at floor edges, to transfer the weight of the veneer to the building structure. In multi-story buildings, such a system is called a curtain wall

Curtain wall

A curtain wall is an outer covering of a building in which the outer walls are non-structural, but merely keep out the weather. As the curtain wall is non-structural it can be made of a lightweight material reducing construction costs. When glass is used as the curtain wall, a great advantage is...

.

Materials

Masonry veneers can be made of any concrete

Concrete

Concrete is a composite construction material, composed of cement and other cementitious materials such as fly ash and slag cement, aggregate , water and chemical admixtures.The word concrete comes from the Latin word...

, manufactured clay, artificial stone or natural stone product. Typically, masonry

Masonry

Masonry is the building of structures from individual units laid in and bound together by mortar; the term masonry can also refer to the units themselves. The common materials of masonry construction are brick, stone, marble, granite, travertine, limestone; concrete block, glass block, stucco, and...

 refers to individual units that are placed in a mortar bed, making a distinction with panelized products.

If a masonry veneer is used over a framed wall, sheathing and a moisture barrier are required to assure the weather tightness of the assembly.

Rain screens

A variant on masonry veneer is the rain screen veneer. Rain screens are ventilated at the top and bottom of the cavity to prevent wind-driven rain from being driven into the building by unbalanced pressure. Such systems are typically encountered in areas where blowing rain is a significant concern.

Thermal performance

Buildings with masonry veneer walls can be better at cooling down during extended periods of hot weather than framed and sided buildings - making conditions more comfortable at night during summer.

Reverse masonry veneer walls have the brickwork inside and lightweight frame and cladding outside. This has the advantage of providing the thermal mass

Thermal mass

Thermal mass is a concept in building design which describes how the mass of the building provides "inertia" against temperature fluctuations, sometimes known as the thermal flywheel effect...

on the inside of a building.