Tn 18A web-nov06. indd

COMBINING MATERIALS

Movement joints must be provided in multi-wythe brick and 

concrete masonry walls. Expansion joints are placed in the 

brick wythe, and control joints are placed in the concrete 

masonry, although they do not necessarily have to be 

aligned through the wall.

Bond Breaks

Concrete and concrete masonry have moisture and 

thermal movements that are considerably different from 

those of brick masonry. Floor slabs and foundations also 

experience different states of stress due to their loading 

and support conditions. Therefore, it may be necessary 

to separate brickwork from these elements using a bond 

break such as building paper or flashing. Such bond 

breaks should be provided between foundations and 

walls; between slabs and walls; and between concrete 

and clay masonry, to allow independent movement while 

still providing gravity support. Typical methods of breaking 

bond between walls and slabs, and between walls and 

foundations are shown in 

Figure 11

.

When bands of clay brick are used in concrete masonry 

walls, or when bands of concrete masonry or cast stone are 

used in clay brick walls, differences in material properties 

may cause mortar joints or masonry units to crack. Such 

problems can be easily avoided by using bands of brickwork featuring brick of a different color, size or texture or 

a different bond pattern. If, however, a different material is used for the band, it may be prudent to install a bond 

break between the two materials, provide additional movement joints in the wall, or place joint reinforcement in the 

bed joints of the concrete masonry to reduce the potential for cracking.

Bond Break

Brick

Insulation

CMU

Flashing as

Bond Break

Concrete Roof

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