Previous Topic

Brick Veneer (also Natural Stone)

Brick Veneer (also Natural Stone)

 

Brick and natural stone veneer are available in a wide variety of shapes, sizes, and colors. The most common brick is the modular brick which is 7⅝ inches long by 2¼ inches tall by 3⅝ inches deep. Queen and king size bricks are occasionally encountered. Natural stone is occasionally used as adhered masonry veneer. Refer to the Adhered Masonry Veneer section for more information.

Brick and natural stone have been used since ancient times and are still widely used, although natural stone has been replaced by adhered masonry veneer in many newer houses. Brick and natural stone are also called anchored veneer because the veneer is attached to the structural wall using metal wall ties.

 

Two images. Above image is captioned "If supported on the foundation, it is probably natural stone veneer." Image below is captioned "If not supported on the foundation, it is probably adhered veneer. Note absence of weep screed at the transition between framing and foundation. Flashing alone is not adequate."
 

Brick and natural stone veneer are usually installed by placing the material on a structural support such as a foundation ledge or on a lintel (L shaped steel). Both veneer types must be installed over sheathed walls and a water-resistive barrier. They are typically installed with an air space between the material and the wall.

Brick and natural stone veneer may be supported by wood framing (except in high seismic risk zones). The veneer should be supported by a lintel when supported by framing. The lintel may be anchored to the studs using lag screws, or the lintel may bear on at least three rafters. Brick support details are often concealed during a home inspection. Home inspectors should look for cracks in the bricks and mortar, and for roof framing deformation as clues that brick support details may be improperly installed.

Bricks can expand due to changes in temperature and moisture. Brick veneer that is supported by different structural components may move at different rates. This expansion and movement can cause cracking. Expansion (movement) joints should be placed at various locations to accommodate expansion and movement. For example, an expansion joint should be installed where brick and stone veneer supported by framing meets veneer supported by the foundation.

An expansion joint is formed by omitting mortar from between bricks and filling the joint with a backer rod and sealant. Expansion joints are uncommon in residential construction; however, their absence can be the explanation for some cracks observed in brick veneer.

A steel lintel is usually installed to support the veneer above openings such as windows and doors. Each end of a lintel should bear on at least four inches of the supporting veneer; additional bearing distance is recommended for lintels over large openings such as garage vehicle doors. Lintels should be covered with a rust-resistant coating such as paint. Rusted lintels may expand and cause cracks in the veneer around openings.

 

Diagram depicting brick support over roof by steel angle.
 
Diagram depicting brick movement joint between roof and foundation
 

Mortar is used to bind brick and natural stone veneer to each other. Bed joints (horizontal joints) and head joints (vertical joints) are usually about ⅜ thick and may vary between ¼ and ½ inch thick. Joints are sometimes up to ¾ inch thick, especially the bed joint below the first course; however, joints this thick are subject to cracking.

Mortar joints are usually tooled for aesthetic reasons, and to help shed water. Joints that provide a shelf where water can collect (such as the raked and struck joints) are not recommended. Home inspectors should report the presence of these mortar joints, and should recommend monitoring for deterioration of bricks and mortar.

 

Diagram depicting brick mortar joints
 

 

The brick industry uses many terms to identify bricks when installed. The following illustration presents some of the most common terms.

 
Diagram depicting common brick terms.
 

Typical Defects Typical defects that home inspectors should report include:

  1. absent and deteriorated flashing and sealant around doors, windows, and other penetrations,
  2. absent and improperly installed flashing and kick out flashing at wall intersections,
  3. cracked and deteriorated mortar,
  4. cracks run through bricks and stone (often more serious than cracks in mortar),
  5. different color mortar (evidence of repairs),
  6. bricks and stone rotating away from the structure,
  7. rusted lintels,
  8. absent and improperly installed weep holes at currently required locations including foundation and above and below windows and doors (weep holes requirement is relatively recent), deteriorated or spalling brick and mortar,
  9. improper mortar joints that may allow water to deteriorate brick and mortar,
  10. efflorescence,
  11. deformed lintels and framing,
  12. absent movement joint where bricks are supported by different components (e.g. framing and foundation).

Standards (1) IRC 2018 Section R703; (2) Brick Industry Association Technical Notes; (3) manufacturer’s instructions.

 

Image is captioned "Acceptable base and counterflashing. Kick out flashing is too small."
 
Image is captioned "No visible counterflashing. Unacceptable raked mortar joint."
 
Image is captioned "White powder is efflorescence, a clue that there may be a water issue."
 
Three images, two on top and one on bottom. Captioned as follows "Three pictures above show significant brick veneer cracking. Upper left and lower pictures show cracks seen on the same side of the house. Upper right picture shows foundation wall crack on the same side of the house."
 
Image is captioned "Weep holes should be above grade. Picture courtesy of Welmoed Sisson."
 
Image is captioned "Different color mortar is a clue that repairs have been made."
 
Image is captioned "Typical rusted lintel."